¹ Kingdom of Saudi Arabia, Royal Embassy, ‘Statement by Saudi Ambassador Al-Jubeir on Military Operations in Yemen’ (25 March 2015) Washington DC <http://www.saudiembassy.net/press-releases/press03251501.aspx>.

² Statement Issued by the Kingdom of Saudi Arabia, the United Arab Emirates, the Kingdom of Bahrain, the State of Qatar and the State of Kuwait, Enclosure to Annex of Identical Letters Dated 26 March 2015 from the Permanent Representative of Qatar to the United Nations Addressed to the Secretary-General and the President of the Security Council (27 March 2015) UN Doc S/2015/217, 5 (Coalition statement in letters to UN, dated 26 March 2015).

³ K Abdallah and S Aboudi, ‘Yemeni Leader Hadi Leaves Country as Saudi Arabia Keeps Up Air Strikes’ (Reuters, 26 March 2015).

⁴ Dalacoura, K, ‘The 2011 Uprisings in the Arab Middle East: Political Change and Geopolitical Implications’ (2012) 88 IA 67Google Scholar.

⁵ Alley, AL, ‘Assessing (In)Security after the Arab Spring: The Case of Yemen’ (2013) 46 PS 721Google Scholar.

⁶ International Crisis Group, ‘Yemen: Enduring Conflicts, Threatened Transition’ (Middle East Report No 125) (3 July 2012) 1 (ICG Report on Yemen, July 2012). For the full text of agreements, see Appendices B and C, ibid 32–8.

⁷ ‘GCC Initiative to End Yemeni Crisis Signed in Riyadh’ (Yemen News Agency (SABA), 23 November 2011) <http://www.sabanews.net/en/news253973.htm>.

⁸ ‘Yemen Witnesses High Voter Turnout That Will End Saleh's Rule’ (Al Arabiya News, 23 February 2012).

⁹ E Gaston, ‘Process Lessons Learned in Yemen's National Dialogue’ (Special Report 342, United States Institute of Peace) (February 2014) 6.

¹⁰ UNSC Res 2140 (26 February 2014) UN Doc S/RES/2140, paras 3, 11, and 15.

¹¹ ‘Yemen to Become Six-Region Federation, Committee Approves’ (Yemen News Agency (SABA), 10 February 2014) <http://www.sabanews.net/en/news341196.htm>.

¹² International Crisis Group, ‘The Huthis: From Sadaa to Sanaa’ (Middle East Report N°154) (10 June 2014) 5 and 14 (note 8).

¹³ AA Jadallah et al., ‘Final Report of the Panel of Experts on Yemen Established Pursuant to Security Council Committee Resolution 2140 (2014)’ (20 February 2015) UN Doc S/2015/125, paras 104–141 (2015 Final Report UN Panel of Experts).

¹⁴ Z Laub, ‘Who Are Yemen's Houthis? Interview with April Longley Alley’ (Council on Foreign Relations, 25 February 2015) <http://www.cfr.org/yemen/yemens-houthis/p36178>. See also BA Salmoni et al., Regime and Periphery in Northern Yemen: The Huthi Phenomenon (RAND National Defense Research Institute 2010) <http://www.rand.org/content/dam/rand/pubs/monographs/2010/RAND_MG962.pdf>.

¹⁵ 2015 Final Report UN Panel of Experts (n 13) paras 82 and 102–74.

¹⁶ ‘Yemen Fuel Subsidy Cuts Hit Poor Hardest’ (IRIN News, 25 August 2014) <http://www.irinnews.org/report/100535/yemen-fuel-subsidy-cuts-hit-poor-hardest>.

¹⁷ AI Al-Moshki, ‘Houthi Leader: “Topple the Falling Government”’ (Yemen Times, 19 August 2014) <http://www.yementimes.com/en/1808/news/4212/Houthi-leader-%E2%80%9CTopple-the-failing-government%E2%80%9D.htm>.

¹⁸ 2015 Final Report UN Panel of Experts (n 13) para 133.

¹⁹ See Peace and National Partnership Agreement, signed on 21 September 2014, reproduced at <http://www.sabanews.net/en/news369204.htm>.

²⁰ Record of UN Security Council Meeting 7381 (12 February 2015) UN Doc S/PV.7381, 2.

²¹ ibid 3.

²² UNSC Res 2201 (15 February 2015) UN Doc S/RES/2201, para 7.

²³ MA Kalfood et al., ‘Suicide Attacks at Mosques in Yemen Kill More Than 130’ (New York Times, 20 March 2015).

²⁴ K Al-Karimi, ‘Houthis Warn against Foreign Military Intervention (Yemen Times, 25 March 2015) <http://www.yementimes.com/en/1871/news/5001/Houthis-warn-against-foreign-military-intervention.htm>.

²⁵ See the official website ‘Operation Renewal of Hope—The Coalition’, <http://www.operationrenewalofhope.com/the-coalition/#sthash.3LZajTRE.qF2gjIyi.dpbs>.

²⁶ ie Kuwait, Bahrain, Qatar, the United Arab Emirates, Jordan, Morocco, Egypt and Sudan.

²⁷ United States of America, The White House Office of the Press Secretary, ‘Statement by NSC Spokesperson Bernadette Meehan on the Situation in Yemen’ (25 March 2015) <http://www.whitehouse.gov/the-press-office/2015/03/25/statement-nsc-spokesperson-bernadette-meehan-situation-yemen> (White House Statement on Yemen, dated 25 March 2015); United Kingdom, Parliament, ‘Saudi Arabia: Yemen: Written question - HL1125’ (14 July 2015) <http://www.parliament.uk/business/publications/written-questions-answers-statements/written-question/Lords/2015-07-06/HL1125>. N Thompson and I Torre, ‘Yemen: Who's Joining Saudi Arabia's Fight against the Houthis?’ (CNN, 30 March 2015); P Fabricius, ‘What Are African Countries Really Doing in Yemen?’ (Institute for Security Studies Africa, 7 May 2015) <http://www.issafrica.org/iss-today/what-are-african-countries-really-doing-in-yemen>.

²⁸ A Ahmed, ‘Somalia Lends Support to Saudi-led Fight against Houthis in Yemen’ (The Guardian, 7 April 2015).

²⁹ Kingdom of Saudi Arabia, Royal Embassy, ‘Saudi Ambassador: Operation Decisive Storm Achieved Its Objectives’ (22 April 2015) Washington DC, <http://www.saudiembassy.net/press-releases/press04221501.aspx>.

³⁰ I Black, ‘Yemen Conflict Continues Despite Saudi Arabia Claiming to Have Ended Campaign’ (The Guardian, 22 April 2015).

³¹ ‘Yemen Humanitarian Ceasefire to Begin’ (Al Arabiya News, 12 May 2015).

³² On 15 June 2015, a first round of consultations between Yemeni factions officially started in Geneva, but ended unsuccessfully a few days later. See ‘UN Launches New Aid Appeal as Yemen Faces “Looming Catastrophe”’ (UN News Centre, 19 June 2015). In July 2015, the Saudi-led coalition launched a major offensive, dubbed ‘Operation Golden Arrow’, and has since driven the Houthis from Aden and other parts of southern Yemen. President Hadi returned to Yemen, after six months in exile, on 22 September 2015. See S Almosawa and K Fahim, ‘Abdu Rabbu Mansour Hadi, Deposed President, Returns to Yemen’ (New York Times, 22 September 2015).

³³ ie all Member States of the Gulf Cooperation Council except for Oman.

³⁴ Coalition statement in letters to UN, dated 26 March 2015 (n 2).

³⁵ ibid 4–5.

³⁶ ibid 5. The letter specifically refers to ‘November 2009’, when several Saudi border guards were killed and injured by Yemen's Houthi rebels in a cross-border incursion, in retaliation for allowing Yemeni troops to attack rebel positions from Saudi territory. This led Saudi Arabia to join the Yemeni government's forces in ‘Operation Scorched Earth’, ie, their sixth and final round of war against the northern Houthi insurgents. The result for the Saudis was detrimental with a loss of over 130 soldiers after months of fighting. See A Orkaby, ‘Saudi Arabia's War with the Houthis: Old Borders, New Lines’ (Policywatch 2404, The Washington Institute) (9 April 2015) <http://www.washingtoninstitute.org/policy-analysis/view/saudi-arabias-war-with-the-houthis-old-borders-new-lines>; C Boucek, ‘War in Saada—From Local Insurrection to National Challenge’ (Carnegie Papers Series Middle East Programme No 110) (April 2010) 11–12; Salmoni et al. (n 14) 155–7.

³⁷ For a transcript of the 25 March 2015 press conference, see ‘Statement by Saudi Ambassador Al-Jubeir on Military Operations in Yemen’ (Saudi-US Relations Information Service (SUSRIS), 26 March 2015) <http://susris.com/2015/03/26/statement-by-saudi-ambassador-al-jubeir-on-military-operations-in-yemen-transcript/> (emphasis added). See also the speech by the Representative of Yemen to the Security Council, again invoking art 51 of the UN Charter: Record of UN Security Council Meeting 7426 (14 April 2015) UN Doc S/PV.7426, 9.See also the message by King Salman bin Abdulaziz Al Saud of Saudi Arabia in Annex to Identical Letters Dated 19 May 2015 from the Permanent Representative of Qatar to the United Nations Addressed to the Secretary-General and the President of the Security Council (21 May 2015) UN Doc S/2015/359, 2: ‘Saudi Arabia and the States members of the coalition responded (…) to the request of the legitimate Government of Yemen (…) in accordance with the principle of self-defence’.

³⁸ Art 2 of the Treaty of Joint Defense and Economic Co-operation Treaty between the States of the Arab League (adopted 17 June 1950, entered into force 22 August 1952) 1 American Foreign Policy 1950–1955 (Basic Documents) 1249.

³⁹ Kingdom of Saudi Arabia, Royal Embassy, ‘Final Communiqué of the 26th Arab League Summit’ (29 March 2015) Washington DC, <http://saudiembassy.net/announcement/announcement03291501.aspx>.

⁴⁰ White House Statement on Yemen, dated 25 March 2015 (n 27).

⁴¹ United Kingdom, Prime Minister's Office, ‘PM Call with King Salman of Saudi Arabia’ (27 March 2015) <http://www.gov.uk/government/news/pm-call-with-king-salman-of-saudi-arabia-27-march-2015>.

⁴² Republic of France, France Diplomatie, ‘Yemen – Situation’ (26 March 2015) <http://www.diplomatie.gouv.fr/en/country-files/yemen/france-and-yemen/events-7685/article/yemen-situation-26-03-15>.

⁴³ Canada, Department of Foreign Affairs, Trade and Development, ‘Minister Nicholson Concerned by Crisis in Yemen’ (27 March 2015) <http://www.international.gc.ca/media/aff/news-communiques/2015/03/27d.aspx?lang=eng>.

⁴⁴ European Union, External Action Service, ‘Statement of the High Representative and Vice President Federica Mogherini on the Situation in Yemen’ (26 March 2015) <http://eeas.europa.eu/statements-eeas/2015/150326_02_en.htm>.

⁴⁵ UN Secretary-General Ban Ki-moon, ‘Noting Saudi Araba Has Begun Military Operations in Yemen, Secretary-General Says Negotiations Remain Only Option for Resolving Yemeni Crisis’ (Press Release) (26 March 2015) UN Doc SG/SM/16621. See also Statement by the President of the Security Council, (22 March 2015) UN Doc S/PRST/2015/8, 3; and UNSC Res 2201 (15 February 2015) UN Doc S/RES/2201, 9.

⁴⁶ Annex to the Letter Dated 17 April 2015 from the Permanent Representative of the Islamic Republic of Iran to the United Nations Addressed to the Security Council (17 April 2015) UN Doc S/2015/263. See also Record of UN Security Council Meeting 7527 (30 September 2015) UN Doc S/PV.7527, 82 (Iran), condemning the ‘aggression against Yemen’ before the Security Council.

⁴⁷ See tweet dated 9 April 2015 at Ayatollah Khamenei's official Twitter page: <http://twitter.com/khamenei_ir>.

⁴⁸ Russian Federation, Ministry of Foreign Affairs, ‘Comment by the Foreign Ministry on the Situation in Yemen’ (26 March 2015) <http://www.mid.ru/bdomp/brp_4.nsf/e78a48070f128a7b43256999005bcbb3/20ca325c9ebff5d943257e140048cd74!OpenDocument>.

⁴⁹ ‘Saudi-Led Coalition Operation in Yemen Has No Legal Foundation – Lavrov’ (Sputnik News, 6 April 2015) <http://sputniknews.com/world/20150406/1020533752.html>.

⁵⁰ MR Gordon and E Schmitt, ‘Tensions Flare Between Iraq and Saudi Arabia in U.S. Coalition’ (New York Times, 15 April 2015).

⁵¹ Republic of Iraq, Ministry of Foreign Affairs, ‘Foreign Minister: The Summit Needs to Exert Efforts to Find Proper Solution to the Yemeni Issue’ (29 March 2015) <http://www.mofa.gov.iq/en/news/foreign-minister-the-summit-needs-to-exert-efforts-to-find-proper-solution-to-the-yemeni-issue>.

⁵² Record of UN Security Council Meeting 7426 (14 April 2015) UN Doc S/PV.7426.

⁵³ UNSC Res 2216 (14 April 2015) UN Doc S/RES/2216.

⁵⁴ ibid. See also the List Established and Maintained by the Security Council Committee Established pursuant to Resolution 2140 (2014) with respect to Individuals, Entities, Groups, or Undertakings at <http://www.un.org/sc/committees/2140/sanctions_list.shtml>.

⁵⁵ eg Record of UN Security Council Meeting 7426 (14 April 2015) UN Doc S/PV.7426, 7 (France and Chad) and 8 (Jordan).

⁵⁶ ibid 6 (Lithuania and France), 7 (Chad) and 8 (Jordan).

⁵⁷ Save perhaps by Yemen, which reiterated its reliance on art 51 UN Charter. ibid 9.

⁵⁸ ibid 2.

⁵⁹ ibid 7.

⁶⁰ See the statements made by the Permanent Representatives of China, Chile, and Nigeria. On the contrary, the United States, United Kingdom, and Chad expressed support for the efforts of the Gulf Cooperation Council. Record of UN Security Council Meeting 7426 (14 April 2015) UN Doc S/PV.7426.

⁶¹ ibid 2 (emphasis added).

⁶² ibid 5 (emphasis added).

⁶³ R Chesney, ‘U.S. Support for the Saudi Air Campaign in Yemen: The Legal Issues’ (Lawfare, 15 April 2015) <http://www.lawfareblog.com/us-support-saudi-air-campaign-yemen-legal-issues>; A Deeks, ‘International Legal Justification for the Yemen Intervention: Blink and Miss It’ (Lawfare, 30 March 2015) <http://www.lawfareblog.com/international-legal-justification-yemen-intervention-blink-and-miss-it>; N Weizmann, ‘International Law on the Saudi-Led Military Operations in Yemen’ (Just Security, 27 March 2015) <http://justsecurity.org/21524/international-law-saudi-operation-storm-resolve-yemen/>; J Dyke, ‘Is the Saudi War on Yemen Legal?’ (IRIN News, 3 April 2015) <http://www.irinnews.org/report/101320/is-the-saudi-war-on-yemen-legal>.

⁶⁴ Coalition statement in letters to UN, dated 26 March 2015 (n 2).

⁶⁵ ibid 5. The letter makes clear that the latter refers not to the Houthis, but to ‘Al-Qaida and Islamic State in Iraq and the Levant’.

⁶⁶ ARM Hadi, ‘Yemen's President: The Houthis Must Be Stopped’ (New York Times, 12 April 2015).

⁶⁷ Letter Dated 24 April 2015 from the Permanent Representative of Qatar to the United Nations Addressed to the President of the Security Council (27 April 2015) UN Doc S/2015/279, 2 (referring to a ‘direct threat … to peace and security in our region’).

⁶⁸ See below section V: ‘A Valid Request for Military Assistance by President Hadi?’

⁶⁹ Coalition statement in letters to UN, dated 26 March 2015 (n 2) 4–5.

⁷⁰ ibid 5.

⁷¹ Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States) (Merits) [1986] ICJ Rep 14, paras 195 and 199 (ICJ Nicaragua case).

⁷² See below section V: ‘A Valid Request for Military Assistance by President Hadi?’.

⁷³ Annex to UNGA Res 3314(XXIX) (14 December 1974) UN Doc A/RES/3314 (XXIX) (UNGA Resolution 3314 on aggression).

⁷⁴ North Atlantic Treaty Organization, ‘Statement by the North Atlantic Council’ (12 September 2001) <http://www.nato.int/docu/pr/2001/p01-124e.htm>: ‘The Council agreed that if it is determined that [the 9/11] attack was directed from abroad against the United States, it shall be regarded as an action covered by Article 5 of the Washington Treaty, which states that an armed attack against one or more of the Allies in Europe or North America shall be considered an attack against them all.’

⁷⁵ See on this eg C Gray, International Law and the Use of Force (3rd edn, Oxford University Press 2008) 132–47; T Ruys, ‘Armed Attack’ and Article 51 of the UN Charter (Cambridge University Press 2010) 419–510; Tams, C, ‘The Use of Force against Terrorists’ (2009) 20 EJIL 359Google Scholar.

⁷⁶ 2015 Final Report UN Panel of Experts (n 13) paras 71–101.

⁷⁷ ibid paras 94–99.

⁷⁸ Coalition statement in letters to UN, dated 26 March 2015 (n 2) 4.

⁷⁹ The same is true for the White House Statement on Yemen, dated 25 March 2015 (n 27). In a similar vein, in the Security Council debate of 14 April 2015, not a single Council Member made any express allegations of Iranian involvement (only Yemen did so during its intervention in the debate).

⁸⁰ Statement by Mr Alyemany, Permanent Representative of Yemen to the UN: ‘I would therefore urge the Council to silence the drums of war being beaten by the promotors of the coup, as well as the sedition they seek to fuel in my country, which is incited by Iran's ambition here.’ Record of UN Security Council Meeting 7411 (22 March 2015) UN Doc S/PV.7411, 4; Hadi (n 67): ‘The Houthi rebels are puppets of the Iranian government, and the government of Iran … only cares about achieving regional hegemony.’

⁸¹ See for just one example: D Bednarz et al., ‘Proxy War in Yemen: Saudi Arabia and Iran Vie for Regional Supremacy’ (Der Spiegel, 3 April 2015).

⁸² ICJ Nicaragua case (n 71) para 195 (emphasis added).

⁸³ This relates to a somewhat broader type of interaction between the State and armed group, which ‘would have to be decided on the basis of all the circumstances’. B Ferencz, Defining International Aggression. The Search for World Peace: A Documentary History and Analysis (Oceana Publications 1975) vol 2, 40; Ruys (n 75) 388–9 and 415–19.

⁸⁴ ICJ Nicaragua case (n 71) para 195.

⁸⁵ See Ruys (n 75) 415–17. It may be noted that, in the Armed Activities case, the ICJ only discusses the first prong of art 3(g) of UNGA Resolution 3314 (1974), ie the ‘sending by or on behalf of a State’ of armed bands. It does not go into the second element, ie the ‘substantial involvement’ of a State in attacks by non-State actors. See Case Concerning Armed Activities on the Territory of the Congo (Democratic Republic of the Congo v. Uganda) (Merits) [2005] ICJ Rep 168, para 146 (ICJ Armed Activities case).

⁸⁶ See A Randelzhofer and G Nolte, ‘Article 51’ in B Simma et al. (eds), The Charter of the United Nations: A Commentary (3rd edn, Oxford University Press 2012) vol 2, 1415–16; Ruys (n 75) 486ff.

⁸⁷ Randelzhofer and Nolte (n 86) 1416.

⁸⁸ Talmon, S, ‘The Responsibility of Outside Powers for Acts of Secessionist Entities’ (2009) 58 ICLQ 515–16CrossRefGoogle Scholar; C Stahn, ‘Terrorist Acts as “Armed Attack”: The Right to Self-Defense, Article 51 (1/2) of the UN Charter, and International Terrorism’ (2003) 27 Fletcher Forum of World Affairs 51: ‘the provision of financial, logistical, or other support on a large scale may be an indication of the state's “overall control” over the group. In this case, the defending state could use force in self-defense against the terrorist-linked state.’ See also U Leanza, ‘The Historical Background’ in M Politi and G Nesi (eds), The International Criminal Court and the Crime of Aggression (Ashgate Publishing 2004) 8.

⁸⁹ Prosecutor v Tadić (Judgement) IT-94-1-A, A Ch (15 July 1999) para 137.

⁹⁰ Case Concerning Application of the Convention on the Prevention and Punishment of the Crime of Genocide (Bosnia and Herzegovina v Serbia and Montenegro) (Merits) [2007] ICJ Rep 43, para 404 (ICJ Bosnian Genocide case).

⁹¹ 2015 Final Report UN Panel of Experts (n 13) para 153. In a strongly worded letter to the UN Security Council, Iran vehemently denied all involvement in relation to this incident: ‘the allegations, whether about the ship's ownership or arms shipment from Iran to Yemen, are absurd fabrications and have no basis or validity’.

⁹² ‘Yemen Crisis: Kerry Warns Iran over Houthi Rebel “Support”’ (BBC News, 9 April 2015).

⁹³ Iranian General Esmail Ghan reportedly stated that the ‘defenders of Yemen’ were trained by Iranian forces. A Knutsen, ‘2015 Yemen Crisis Situation Report: May 27’ (American Enterprise Institute Critical Threats, 27 May 2015) <http://www.criticalthreats.org/yemen/yemen-crisis-situation-reports-may-27-2015>. See also M Knights and A Mello, ‘The Saudi-UAE War Effort in Yemen (Part 1): Operation Golden Arrow in Aden’ (The Washington Institute, 10 August 2015) <http://www.washingtoninstitute.org/policy-analysis/view/the-saudi-uae-war-effort-in-yemen-part-1-operation-golden-arrow-in-aden>.

⁹⁴ 2015 Final Report UN Panel of Experts (n 13) para 56.

⁹⁵ Mohammed Ali Al-Houthi, head of the Supreme Revolutionary Council, reportedly claimed: ‘There is no Iranian intervention in Yemen and the Saudis can inspect the missiles [we fire] and see if these are made in Iran, Russia or America … We say that they are purely Yemeni-made.’ See AP, ‘Top Yemen Shiite Rebel Welcomes UN Peace Talks’ (The Jordan Times, 4 June 2015) <http://www.jordantimes.com/news/region/top-yemen-shiite-rebel-welcomes-un-peace-talks>. Moreover, see Letter Dated 12 May 2015 from the Permanent Representative of the Islamic Republic of Iran to the United Nations Addressed to the President of the Security Council (13 May 2015) UN Doc S/2015/335: ‘I wish to reiterate our position as reflected in the letters of 23 March 2015 (S/2015/207), 9 April 2015 (S/2015/249) and 17 April 2015 (S/2015/263), and to categorically reject such allegations that are wilfully fabricated’. Finally, Ayatollah Khamenei pointedly tweeted on 6 May 2015: ‘They ask why #Iran helps Yemenis. We wanted to ship medicine. #AnsarAllah doesn't need our weapons; they run all #Yemen's military bases.’

⁹⁶ M Milani, ‘Iran's Game in Yemen – Why Tehran Isn't to Blame for the Civil War’ (Foreign Affairs, 19 April 2015).

⁹⁷ B Whitaker, ‘Yemen and Iran: What's Really Going On?’ (Al-Bab, 30 March 2015) <http://www.al-bab.com/blog/2015/march/yemen-iran.htm#sthash.pxX55Kqy.PVtdBvMX.dpbs>.

⁹⁸ Interview with Saudi Ambassador to the United States Adel bin Ahmed Al-Jubeir (The Situation Room with Wolf Blitzer (CNN), 26 March 2015) <http://www.saudiembassy.net/_pvw37F68B18/announcement/announcement03271501.aspx>.

⁹⁹ United States, Department of State, ‘Daily Press Briefing’ (12 February 2015) <http://www.state.gov/r/pa/prs/dpb/2015/02/237453.htm>.

¹⁰⁰ Coalition statement in letters to UN, dated 26 March 2015 (n 2) 5 (emphasis added).

¹⁰¹ White House Statement on Yemen, dated 25 March 2015 (27).

¹⁰² It follows that this would then be framed as an exercise of collective self-defence in support of Saudi Arabia on the part of the other members of the coalition of the willing.

¹⁰³ See (n 37).

¹⁰⁴ ICJ Nicaragua case (n 71) para 194.

¹⁰⁵ Randelzhofer and Nolte (n 86) 1427. Customary practice indeed reveals that, for action in self-defence to be lawful, there should be a reasonably close proximity in time between the ‘armed attack’ and the resulting action in self-defence. See Ruys (n 75) 99ff.

¹⁰⁶ United States of America, The White House Office of the Press Secretary, ‘President Bush Delivers Graduation Speech at West Point’ (1 June 2002) <http://georgewbush-whitehouse.archives.gov/news/releases/2002/06/20020601-3.html>.

¹⁰⁷ Randelzhofer and Nolte (n 86) 1423.

¹⁰⁸ Letter of US Secretary of State Daniel Webster to Special Minister Ashburton in relation to the Caroline incident, dated 27 July 1842, British and Foreign State Papers (1840–41) vol XXIX, 1137–8.

¹⁰⁹ See Ruys (n 75) 305–42.

¹¹⁰ ibid.

¹¹¹ ICJ Armed Activities case (n 85) paras 143 and 148 (‘Article 51 of the Charter … does not allow the use of force by a State to protect perceived security interests’).

¹¹² On the imminence requirement, see eg N Lubell, ‘The Problem of Imminence in an Uncertain World’ in M Weller (ed), The Oxford Handbook of the Use of Force in International Law (Oxford University Press 2015).

¹¹³ See (n 37).

¹¹⁴ Coalition statement in letters to UN, dated 26 March 2015 (n 2) 5.

¹¹⁵ F Gardner, ‘Yemen Crisis: Why Gulf States Went to War with the Houthis’ (BBC News, 1 May 2015).

¹¹⁶ 2015 Final Report UN Panel of Experts (n 13) paras 82–84.

¹¹⁷ United States, Department of State, Foreign Relations of the United States, Diplomatic Papers (1945) General: the United Nations (1967) 818.

¹¹⁸ Coalition statement in letters to UN, dated 26 March 2015 (n 2) 4–5.

¹¹⁹ A Randelzhofer and O Dörr, ‘Article 2(4)’ in B Simma et al. (eds), The Charter of the United Nations: A Commentary (3rd edn, Oxford University Press 2012) vol 1, 216.

¹²⁰ See Christakis, T and Mollard-Bannelier, K, ‘Volenti Non Fit Injuria? Les Effets du Consentement à l'Intervention Militaire’ (2004) 50 AFDI 112CrossRefGoogle Scholar.

¹²¹ Declaration on Principles of International Law concerning Friendly Relations and Co-operation among States in accordance with the Charter of the United Nations, UNGA Res 2625(XXV) (24 October 1970) UN Doc A/RES/25/2625 (Friendly Relations Declaration 1970).

¹²² Randelzhofer and Dörr (n 119) 214.

¹²³ It follows that there is no need to conceptualize the territorial State's ‘consent’ as a ‘circumstance precluding wrongfulness’ in terms of the Articles on the International Law Commission's Responsibility of States for Internationally Wrongful Acts (ARSIWA), which raises the issue of the peremptory character of the prohibition on the use of force (which some claim to be limited to a core prohibition of ‘aggression’ only). See Annex to UNGA Res 56/83 (28 January 2002) UN Doc A/56/83.

¹²⁴ However, Gerhard Hafner described this term as a contradictio in se. He suggests employing the phrase ‘military assistance with prior consent’ instead. See G Hafner (Rapporteur), ‘Present Problems of the Use of Force in International Law – Sub-group: Intervention by Invitation’, Institut de Droit International Tenth Commission, Naples Session (2009) <http://www.idi-iil.org/idiE/navig_ann_2009.html> 372–5. Eliav Lieblich also rejects the term and adopts the more neutral concept of ‘consensual intervention’. See E Lieblich, International Law and Civil War: Intervention and Consent (Routledge 2013) 11–13.

¹²⁵ UNGA Resolution 3314 on aggression (n 73): ‘Any of the following acts … shall … qualify as an act of aggression: … (e) The use of armed forces of one State which are within the territory of another State with the agreement of the receiving State, in contravention of the conditions provided for in the agreement or any extension of their presence in such territory beyond the termination of the agreement.’

¹²⁶ The preamble of UNSC Resolution 387(1976) (UN Doc S/RES/387, 31 March 1976) refers to ‘the inherent and lawful right of every State, in the exercise of their sovereignty, to request assistance from any other State or group of States’.

¹²⁷ See in particular art 4(1) of the Institut de Droit International Resolution on Military Assistance on Request (Rapporteur: M Gerhard Hafner) (8 September 2011) Rhodes Session, <http://www.idi-iil.org/idiE/resolutionsE/2011_rhodes_10_C_en.pdf> (IDI Rhodes Resolution).

¹²⁸ ICJ Nicaragua case (n 71) para 246 (emphasis added).

¹²⁹ ICJ Armed Activities case (n 85) para 105.

¹³⁰ Randelzhofer and Dörr (n 119) 214–15.

¹³¹ O Corten, Le Droit contre la Guerre (2nd edn, Editions Pedone 2014) 437; Randelzhofer and Dörr (n 119) 216.

¹³² Arts 48–58 of the Vienna Convention on the Law of Treaties (adopted 23 May 1969, entered into force 27 January 1980) 1155 UNTS 331.

¹³³ Indeed, ‘retroactive consent by a compliant Government – installed thanks to the foreign military intervention – is irredeemably flawed, since in such a case the foreign State actually invites itself’. Y Dinstein, Non-International Armed Conflicts in International Law (Cambridge University Press 2014) 80. A State can also issue prior consent through a treaty, although in that case ‘an additional ad hoc request is still required in the specific case’. ibid 81; see also art 4(2)–(3) of the IDI Rhodes Resolution (n 127).

¹³⁴ See art 13 ARSIWA (n 123). It follows that, without consent at the time of the intervention, Article 2(4) is breached. Corten (n 131) 437.

¹³⁵ J Crawford et al., The Law of International Responsibility (Oxford University Press 2010) 444. See also ICJ Armed Activities case (n 85) para 52 and art 6(1) IDI Rhodes Resolution (n 127).

¹³⁶ Hafner (n 124) 396.

¹³⁷ Gray (n 75) 99.

¹³⁸ Hafner (n 124) 396–402; Corten (n 87) 453; Doswald-Beck, L, ‘The Legal Validity of Military Intervention by Invitation of the Government’ (1985) 56 BYBIL 199–200Google Scholar.

¹³⁹ For example, with regard to the state of anarchy in Somalia, the UN Secretary-General noted that ‘At present no government exists in Somalia that could request and allow [a] use of force.’ Letter dated 29 November 1992 from the Secretary-General addressed to the President of the Security Council (30 November 1992) UN Doc S/24868, 3. Moreover, when Albania descended into anarchy in 1997, it requested a group of countries ‘to participate with a military or a police force in the protection of humanitarian activities in Albania’. However, it also expressed the need for ‘such a force [to] also have the necessary support and authorization of the Security Council’. Letter Dated 28 March 1997 from the Permanent Representative of Albania to the United Nations Addressed to the President of the Security Council (28 March 1997) UN Doc S/1997/259, 1.

¹⁴⁰ Corten (n 131) 466–7. For an overview of State practice, see Hafner (n 124) 398.

¹⁴¹ G Nolte, ‘Intervention by Invitation’, 1702 MPEPIL, para 18.

¹⁴² S Talmon, Recognition of Governments in International Law (Oxford University Press 1998) 149: ‘widespread recognition, especially by the United Nations or regional organizations, of the requesting authority in exile as a government will normally secure that a request is regarded as a valid justification of the military intervention to (re-)install the government in exile’ (emphasis added). See also (n 139). Corten further clarifies the impact of the position of United Nations’ organs on the element of international recognition, in particular with regard to the cases of the Republic of Korea in 1948–50 and the Dominican Republic in 1965. See (n 131) 454–6.

¹⁴³ H Lauterpacht, Recognition in International Law (Cambridge University Press 1947) 141.

¹⁴⁴ ibid.

¹⁴⁵ ibid 93–4.

¹⁴⁶ For example, Nolte (n 141) mentions: ‘Since the end of the Cold War the democratic legitimacy of a government has been emphasized more strongly concerning the determination of the legality of an invitation to intervene.’ Fox also points out: ‘when two factions claim to represent a state and one has a clear electoral mandate, [the United Nations] is increasingly unlikely to prefer effective control to democratic legitimacy’. G Fox, ‘Intervention by Invitation’ in M Weller (ed), The Oxford Handbook of the Use of Force in International Law (Oxford University Press 2015) 835.

¹⁴⁷ d'Aspremont, J, ‘Legitimacy of Governments in the Age of Democracy’ (2006) 38 NYUJIntlLaw&Pol 908–9Google Scholar. See also Hafner (n 124) 401.

¹⁴⁸ Corten (n 131) 466–71.

¹⁴⁹ UNSC Res 940 (31 July 1994) UN Doc S/RES/940.

¹⁵⁰ Gray (n 75) 56.

¹⁵¹ Record of UN Security Council Meeting 7125 (3 March 2014) UN Doc S/PV.7125, 3–4.

¹⁵² ‘Ukraine's Yanukovych Asked for Troops, Russia Tells UN’ (BBC News, 4 March 2014).

¹⁵³ Record of UN Security Council Meeting 7125 (3 March 2014) UN Doc S/PV.7125, 7.

¹⁵⁴ D Wisehart, ‘The Crisis in Ukraine and the Prohibition of the Use of Force: A Legal Basis for Russia's Intervention?’ (EJIL: Talk!, 4 March 2014) <http://www.ejiltalk.org/the-crisis-in-ukraine-and-the-prohibition-of-the-use-of-force-a-legal-basis-for-russias-intervention/>.

¹⁵⁵ SL Myers, ‘Ousted Ukrainian Leader, Reappearing in Russia, Says, “Nobody Deposed Me”’ (New York Times, 28 February 2014).

¹⁵⁶ Mr Sergeyev, the (undisputed) Permanent Representative of Ukraine to the United Nations, provided a laconic response to Russia's reliance upon Yanukovych's invitation: ‘Mr. Viktor Yanukovych is no longer a legitimate President of Ukraine … Thus, the request by Mr. Viktor Yanukovych addressed to the President of the Russian Federation to use its military forces in Ukraine may not be regarded as an official request of Ukraine.’ See Letter Dated 4 March 2014 from the Permanent Representative of Ukraine to the United Nations Addressed to the President of the Security Council (5 March 2014) UN Doc S/2014/152.

¹⁵⁷ See section II: ‘Factual Background to the Yemeni Crisis’.

¹⁵⁸ A regularly updated map of the Houthi areas of influence can be found at <http://www.criticalthreats.org/yemen/al-houthi-areas-influence>. For a comprehensive overview of developments in Yemen, see also the compilation of ‘2015 Yemen Crisis Situation Reports’ at <http://www.criticalthreats.org/yemen/yemen-crisis-situation-reports-2015>.

¹⁵⁹ Record of UN Security Council Meeting 7411 (22 March 2015) UN Doc S/PV.7411, 2–3. See also A Aboluhom, ‘Shabwa Tribes Gather in Support of Hadi’ (Yemen Times, 23 February 2015) <http://www.yementimes.com/en/1862/news/4921/Shabwa-tribes-gather-in-support-of-Hadi.htm>; ‘Yemen Crisis: Who is Fighting Whom?’ (BBC News, 26 March 2015). For some, the term ‘Hadi loyalists’ should not be taken too literally. See S Dahlgren and AA Augustin, ‘The Multiple Wars in Yemen (Middle East Research and Information Project, 18 June 2015) <http://www.merip.org/multiple-wars-yemen>.

¹⁶⁰ Record of UN Security Council Meeting 7411 (22 March 2015) UN Doc S/PV.7411, 3.

¹⁶¹ A Mercouris, ‘Yemen, Ukraine and the US “Single Standard”’ (Sputnik News, 27 March 2015) <http://sputniknews.com/columnists/20150327/1020086381.html>. Ms Harf replied to a pointed question regarding the different approach by the United States in Ukraine as compared to Yemen as follows: ‘We've been very clear how we feel about Ukraine. … last time I checked, major parts of Kyiv weren't being taken over by an armed rebel group when President Yanukovych left, so I think it's pretty different.’ United States of America, Department of State, ‘Daily Press Briefing’ (3 April 2015) <http://www.state.gov/r/pa/prs/dpb/2015/04/240324.htm#YEMEN>. See also Z Vermeer, ‘The Jus ad Bellum and the Airstrikes in Yemen: Double Standards for Decamping Presidents?’ (EJIL: Talk!, 30 April 2015) <http://www.ejiltalk.org/the-jus-ad-bellum-and-the-airstrikes-in-yemen-double-standards-for-decamping-presidents/>.

¹⁶² UNSC Res 2201 (15 February 2015) UN Doc S/RES/2201, para 8; Statement by the President of the Security Council (22 March 2015) UN Doc S/PRST/2015/8, 3.

¹⁶³ UNSC Res 2216 (14 April 2015) UN Doc S/RES/2216, 2.

¹⁶⁴ See (n 56).

¹⁶⁵ See eg the White House Statement on Yemen, dated 25 March 2015 (n 27).

¹⁶⁶ See (n 145).

¹⁶⁷ Gray (n 75) 99. See also Lauterpacht (n 143) 94.

¹⁶⁸ Mention has been made of a third school of thought, ie the ‘positive equality’ theory, allowing all parties in a civil war, including non-State actors, to obtain outside assistance. However, leaving aside the issue of possible support to national liberation movements (which is now mostly a historical question), this theory goes against several UNGA resolutions touching upon the non-intervention principle and has been explicitly denounced by the ICJ in the Nicaragua case (see (n 71) paras 209 and 246). Furthermore, it does not find any support in State practice (States have never explicitly claimed a right to deploy troops in a third State at the request of a secessionist movement or a non-State armed group engaged in a civil war). The situation might be different from the moment that these opposing factions have materialized their de facto territorial control over a prolonged period of time, see art 1(2)(b) of the Institut de Droit International Resolution on the Principle of Non-Intervention in Civil Wars (Rapporteur: Dietrich Schindler) (14 August 1975) Wiesbaden Session, <http://www.idi-iil.org/idiE/resolutionsE/1975_wies_03_en.pdf> (IDI Wiesbaden Resolution). However, this is not the case in Yemen and will therefore not be discussed in this article.

¹⁶⁹ The term was used in the Report of the Independent International Fact-Finding Mission on the Conflict in Georgia, vol 2 (September 2009) 277–8 (Georgia Report). See also Fox (n 146) 827–9.

¹⁷⁰ Lieblich (n 124) 130–40.

¹⁷¹ Art 2(1) of the IDI Wiesbaden Resolution (n 168). However, there was significant divergence of views during the debates, so that ‘there was no certainty on whether the resolution reflected lex lata or proposed articles de lege ferenda’. Hafner (n 124) 365.

¹⁷² Doswald-Beck (n 138) 251; Corten (n 131) 513–14; Georgia Report (n 169) 277–8; Gray (n 75) 81.

¹⁷³ British Foreign Office policy document No 148 of 1984, published in (1986) 57 BYBIL 616 (British Foreign Policy Document 1984).

¹⁷⁴ Doswald-Beck (n 138) 243: ‘The duty not to intervene in the civil strife of another State can only be rationalized by perceiving the recipient of the duty as the State in abstracto. The personality of the State as such thus holds the right and for the purpose of this norm the government does not exclusively represent the State.’ See also Christakis and Mollard-Bannelier (n 120) 120.

¹⁷⁵ In general terms, the (customary) principle of non-intervention prohibits coercive acts intended to force a policy change in the target State, irrespective of whether they actually take place in the territory of the target State. See Jamnejad, M and Wood, M, ‘The principle of non-intervention’ (2009) 22 LJIL 367–77CrossRefGoogle Scholar.

¹⁷⁶ UNGA Res 2131(XX) (21 December 1965) UN Doc A/RES/20/2131, para 2: ‘no State shall organize, assist, foment, finance, incite or tolerate subversive, terrorist or armed activities directed towards the violent overthrow of the regime of another State, or interfere in civil strife in another State’. This is repeated in the Friendly Relations Declaration 1970 (n 121). This language seems broad enough to cover a general prohibition on the furnishing of assistance to a government engaged in a civil war. But see UNGA Res 36/103 (9 December 1981) UN Doc A/RES/36/103, para 2(II)(o): ‘The principle of non-intervention and non-interference in the internal and external affairs of States comprehends the following rights and duties: … (o) The duty of a State to refrain from any economic, political or military activity in the territory of another State without its consent.’ (emphasis added).

¹⁷⁷ Friendly Relations Declaration 1970 (n 121) (emphasis added). See also arts 1 and 55 of the UN Charter, and art 1(1) of the International Covenant on Civil and Political Rights (adopted 16 December 1966, entered into force 23 March 1976) 999 UNTS 171 (emphasis added).

¹⁷⁸ S Oeter, ‘Self-Determination’ in B Simma et al. (eds), The Charter of the United Nations: A Commentary (3rd edn, Oxford University Press 2012) vol 1, 326.

¹⁷⁹ Protocol Additional to the Geneva Conventions of 12 August 1949, and relating to the Protection of Victims of International Armed Conflicts (Protocol I) (adopted 8 June 1977, entered into force 7 December 1978) 1125 UNTS 3.

¹⁸⁰ Doswald-Beck (n 138) 203.

¹⁸¹ Fox (n 146) 827.

¹⁸² Corten (n 131) 474. Moreover, consent as a ground precluding wrongfulness is ‘concerned with the relations between the two States in question’. In case of an erga omnes norm, however, the consent of one State will not preclude wrongfulness in relation to all others. See International Law Commission, Draft Articles on Responsibility of States for Internationally Wrongful Acts with Commentaries (2001) 2 UNYBILC 73.

¹⁸³ Y Dinstein, War, Aggression and Self-Defence (5th edn, Cambridge University Press 2011) 119; Garner, J, ‘Questions of International Law in the Spanish Civil War’ (1938) 31 AJIL 68Google Scholar.

¹⁸⁴ Dinstein (n 183) 119.

¹⁸⁵ C Kreß, ‘The Fine Line Between Collective Self-Defense and Intervention by Invitation: Reflections on the Use of Force against ‘IS’ in Syria’ (Just Security, 17 February 2015) <http://justsecurity.org/20118/claus-kreb-force-isil-syria/>: ‘The allied intervention against the Islamic State in Iraq demonstrates, as did shortly before France's intervention against violent non-State fighters in Mali, that State practice does not support the proposition that a government invariably loses the power to invite armed assistance from abroad when it is confronted by internal violence reaching the level of a non-international armed conflict.’ See also Fox (n 146) 828 and D Akande and Z Vermeer, ‘The Airstrikes against Islamic State in Iraq and the Alleged Prohibition on Military Assistance to Governments in Civil Wars’ (EJIL: Talk!, 2 February 2015) <http://www.ejiltalk.org/the-airstrikes-against-islamic-state-in-iraq-and-the-alleged-prohibition-on-military-assistance-to-governments-in-civil-wars/>.

¹⁸⁶ A number of leading proponents of this approach have nonetheless questioned whether the prohibition also encompasses transfer of arms and other support or whether it is limited exclusively to actual deployment of troops abroad. Doswald-Beck (n 138) 251; Corten (n 131) 488. Consider also: Ruys, T, ‘Of Arms, Funding and “Non-lethal Assistance” – Issues Surrounding Third-State Intervention in the Syrian Civil War’ (2014) 13 ChineseJIL 13, paras 46–51Google Scholar.

¹⁸⁷ Gray (n 75) 81, 92 and 94; Doswald-Beck (n 138) 213; Corten (n 131) 472 and 476. Also in this sense: R Kolb, Ius contra Bellum: Le Droit International relative au Maintien de la Paix (2nd edn, Bruylant 2009) 328.

¹⁸⁸ ICJ Nicaragua case (n 71) para 186.

¹⁸⁹ The IDI's Wiesbaden Resolution (n 168) appears to assimilate the term with the concept of a non-international armed conflict in the sense of Common Article 3 of the Geneva Conventions (art 1(1)). By contrast, ‘local disorders or riots’ are clearly excluded from the scope of application (art 1(2)). The 2011 Rhodes Resolution (n 127), however, adopts the higher threshold of art 1 of the Second Additional Protocol to the Geneva Conventions, which applies only to conflicts between a State and one or more non-State groups, and which presupposes some degree of control over territory on the part of the non-State group(s). The 1984 UK Foreign Policy Document (n 173) similarly presupposes that control over territory is divided between the government and the rebels.

¹⁹⁰ Several authors who accept in principle that intervention in a civil war is permissible, accept that the legalizing effect of the consent may be questioned when the intervention would violate the right of self-determination. In this sense: Randelzhofer and Dörr (n 119) 215; O Dörr, ‘Prohibition of Use of Force’, 427 MPEPIL, para 22. Consequently, whereas the majority of scholars conclude that third-State intervention is prohibited as soon as the internal disturbance devolves into civil war, the mentioned authors agree that third-State intervention is prohibited as soon as it violates a people's right to self-determination (even though they subscribe to the ‘government preference’ approach). This indicates that the gap between the two approaches is not as wide as is sometimes thought. Conversely, the Rhodes Resolution (n 127) suggests that, even absent a civil war, military assistance is prohibited ‘when it is exercised in violation of the Charter of the United Nations, of the principles of non-intervention, of equal rights and self-determination of peoples and generally accepted standards of human rights and in particular when its object is to support an established government against its own population’ (art 3(1)). But see Dinstein (133) 80.

¹⁹¹ See Corten (n 131) 476–96. Since Operation Decisive Storm was not launched for such purposes, they will not be discussed further here.

¹⁹² Christakis and Mollard-Bannelier (n 120) 126: ‘Sans ouvrir cet immense débat, il suffit ici de remarquer qu'une telle coopération armée pour lutter contre un mouvement terroriste «authentique» ne semble faire l'objet d'aucune contestation sérieuse dans la pratique internationale.’

¹⁹³ UNSC Res 2133 (27 January 2014) UN Doc S/RES/2133, 1.

¹⁹⁴ On the intervention in Mali, see Van Steenberghe, R, ‘Les Interventions Française et Africaine au Mali au Nom de la Lutte Armée contre le Terrorisme’ (2014) 118 RGDIP 273Google Scholar. See also the contributions by Magi, Starita and Tancredi in (2013) 96 RivDirIntern 551, 561 and 946 (respectively).

¹⁹⁵ Ruys, T and Verlinden, N, ‘Digest of State Practice 1 January–30 June 2014’ (2014) 1 JUFIL 356–7Google Scholar.

¹⁹⁶ UNSC Res 2100 (25 April 2013) UN Doc S/RES/2100, 1 (emphasis added).

¹⁹⁷ The MLNA even declared its readiness to cooperate fully with the French forces (insofar as their actions indeed only targeted terrorist organizations). See Conseil Transitoire de l'Etat de l'Azawad, ‘Récupérations des Villes’ (Communiqué de Presse) (28 January 2013) <http://mnlamov.net/actualites.html?limit=5&start=170>. See also Corten (n 131) 509–10.

¹⁹⁸ Corten (n 87) 509–10; T Christakis and K Bannelier, ‘French Military Intervention in Mali: It's Legal but… Why? Part I: The Argument of Collective Self-Defense’ (EJIL: Talk!, 24 January 2013) <http://www.ejiltalk.org/french-military-intervention-in-mali-its-legal-but-why-part-i/>; T Christakis and K Bannelier, ‘French Military Intervention in Mali: It's Legal but… Why? Part II: Consent and UNSC Authorisation’ (EJIL: Talk!, 25 January 2013) <http://www.ejiltalk.org/french-military-intervention-in-mali-its-legal-but-why-part-2-consent-and-unsc-authorisation/>.

¹⁹⁹ Identical Letters Dated 11 January 2013 from the Permanent Representative of France to the United Nations Addressed to the Secretary-General and the President of the Security Council (14 January 2013) UN Doc S/2013/17 (French statement in letters to UN, dated 14 January 2013).

²⁰⁰ UNSC Res 2100 (25 April 2013) UN Doc S/RES/2100, 1. Christakis and Bannelier (Part II, n 198) also interpret UNSC Resolution 2085 in a way that authorizes all member States to provide military assistance to the Malian Forces. Nonetheless, it can be assumed that the French government would have relied exclusively (or, at least, primarily) on a Security Council authorization, if it would have been a valid legal justification for Opération Serval, quod non. See French statement in letters to UN, dated 14 January 2013 (n 199).

²⁰¹ A Hirsch, ‘Why Malians are Welcoming French Intervention with Open Arms’ (The Guardian, 16 January 2013).

²⁰² Ruys and Verlinden (n 195) 356–7.

²⁰³ It is outside the scope of this article to review the legal justifications of the use of force on Syrian territory. See, however, Henderson, C, ‘Editorial Comment: The Use of Force and Islamic State’ (2014) 1 JUFIL 209Google Scholar and Kreß (n 185).

²⁰⁴ Annex to the Letter Dated 20 September 2014 from the Permanent Representative of Iraq to the United Nations Addressed to the President of the Security Council (22 September 2014) UN Doc S/2014/691, 2. For statements by State officials participating in the coalition, see the following two blogposts: Akande and Vermeer (n 185), and R Van Steenberghe, ‘The Alleged Prohibition on Intervening in Civil Wars Is Still Alive after the Airstrikes against Islamic State in Iraq: A Response to Dapo Akande and Zachary Vermeer’ (EJIL: Talk!, 12 February 2015) <http://www.ejiltalk.org/the-alleged-prohibition-on-intervening-in-civil-wars-is-still-alive-after-the-airstrikes-against-islamic-state-in-iraq-a-response-to-dapo-akande-and-zachary-vermeer/>.

²⁰⁵ According to Van Steenberghe (n 204) ‘the notion of “insurgent movements” [according to the IDI Wiesbaden Resolution (n 168)] actually refers to movements exercising their right of self-determination and being, therefore, supported by a significant part of the population. … I do not think that ISIL benefits from any wide popular support, most of the Syrian and Iraqi population actually fearing the terrorist organization. It could not be seen as exercising any right of self-determination on behalf of such population.’

²⁰⁶ UNSC Resolution 2169 (30 July 2014) UN Doc S/RES/2169, 1. President Obama's letter to Congress furthermore explicitly states: ‘I have also ordered the U.S. Armed Forces to conduct a systematic campaign of airstrikes and other necessary actions against these terrorists in Iraq and Syria.’ United States of America, The White House Office of the Press Secretary, ‘Letter from the President – War Powers Resolution Regarding Iraq’ (23 September 2014) <http://www.whitehouse.gov/the-press-office/2014/09/23/letter-president-war-powers-resolution-regarding-iraq>.

²⁰⁷ This explains why reliance on the ‘intervention by invitation’ doctrine was combined with references to the right of (collective) self-defence. See Henderson (n 203).

²⁰⁸ The letter by Hadi and the statement by the intervening Gulf States clearly reserve the ‘terrorist’ label to groups such as Al-Qaida and Islamic State. Coalition statement in letters to UN, dated 26 March 2015 (n 2) 5.

²⁰⁹ See Gray, Doswald-Beck, Corten and Kolb (n 187). By way of illustration, in 2002, France refused a request for military support from the government of Côte d'Ivoire in its fight against the rebels, since there was ‘insufficient proof of external aggression’, and the principle of non-interference in a State's internal affairs accordingly had to be respected. Quoted in Christakis and Mollard-Bannelier (n 120) 129, note 112 (our translation).

²¹⁰ British Foreign Policy Document 1984 (n 173). See also art 5 of the IDI Wiesbaden Resolution (n 168).

²¹¹ See section IVA: ‘The Right to Collective Self-Defence’.

²¹² Corten (n 131) 496–7. Recall that conditions for a valid request or consent in the respective situations are analogous.

²¹³ Corten (n 131) 497; Lieblich (n 124) 169.

²¹⁴ Gray (n 75) 92.

²¹⁵ In a similar vein, see Vermeer (n 161).

²¹⁶ See eg a contrario, art 3 IDI Wiesbaden Resolution (n 168).

²¹⁷ ICJ Nicaragua case (n 71) para 194.

²¹⁸ In her analysis of relevant State practice, Doswald-Beck notes that ‘It is particularly interesting that the aid given by France [to Chad] was described as being in effect proportionate to the outside help and that France denied openly engaging in the conflict until the presence of Libyan personnel was ascertained. This would indicate an action of collective self-defence in conformity with Article 51 of the Charter and with the principle of proportionality of response in self-defence actions.’ See Doswald-Beck (n 138) 221 (emphasis added). A similar argument is further supported by other scholars, see eg AC Arend and RJ Beck, International Law & the Use of Force (Routledge 1993) 88–9: ‘Under the neutral non-intervention norm, an outside state cannot provide assistance to the rebels at any time. … [If an] outside force has improperly weighed-in to support the rebels [, then] to counter that impermissible intervention, it would be permissible for a third state to provide assistance to the government even if there is a high level of civil strife. This would, it is argued, return the scales to their original position and allow the struggle for self-determination to proceed in accordance with the domestic correlation of forces.’

²¹⁹ See section IVA: ‘The Right to Collective Self-Defence’.

²²⁰ K Zimmermann, ‘2015 Yemen Intervention Map’ (American Enterprise Institute Critical Threats Project, 23 April 2015) <http://www.aei.org/feature/critical-threats-project/>.

²²¹ See section II: ‘Factual Background to the Yemeni Crisis’.

²²² See section III: ‘Reaction by the International Community’.

²²³ UNSC Resolution 2216 (14 April 2015) UN Doc S/RES/2216, 2.

²²⁴ Friendly Relations Declaration 1970 (n 121).

²²⁵ Lauterpacht (n 143) 233.

²²⁶ Gray (n 75) 64. See also Judge Schwebel's Dissenting Opinion in the Nicaragua case (n 71), para 180: ‘it is lawful for a foreign State… to give to a people struggling for self-determination moral, political and humanitarian assistance; but it is not lawful for a foreign State … to intervene in that struggle with force’.

²²⁷ Vashakmadze, M, ‘Legality of Foreign Military Intervention in International Law: Four Case Studies’ (2014) 1 MaxPlanckYrbkUNL 468–70Google Scholar.

²²⁸ Georgia Report (n 169) 279.

²²⁹ See Reisman, WM, ‘Coercion and Self-Determination: Construing Charter Article 2(4)’ (1984) 78 AJIL 642CrossRefGoogle Scholar and D Wippman, ‘Pro-Democratic Intervention by Invitation’ in G Fox and B Roth (eds), Democratic Governance and International Law (Cambridge University Press 2000). See also C Ryngaert, ‘Pro-Democratic Intervention in International Law’ (Working Paper No 53, Institute for International Law K.U. Leuven) (April 2004) 7–10.

²³⁰ Schachter, O, ‘The Legality of Pro-Democratic Invasion’ (1984) 78 AJIL 645CrossRefGoogle Scholar; Franck, TM, ‘The Emerging Right to Democratic Governance’ (1992) 86 AJIL 91CrossRefGoogle Scholar: ‘legitimate governments should be assured of protection from overthrow by totalitarian forces through concerted systemic action after – and only after – the community has recognized that such an exigency has arisen’. See further Dinstein (n 183) 93.

²³¹ Wippman (n 229) 301–3; Fox (n 146) 835–6.

²³² Gray (n 75) 58; Corten (n 131) 467–9. Even Wippman admits that the Haiti precedent is ‘an ambiguous one’. Wippman (n 229) 303.

²³³ See eg Gray (n 75) 56–7.

²³⁴ ibid 56.

²³⁵ Wippman (n 229) 299.

²³⁶ ibid 327.

²³⁷ Vermeer (n 161).