¹ Agreement on the Withdrawal of the United Kingdom of Great Britain and Northern Ireland from the European Union and the European Atomic Energy Community, Brussels and London, January 24, 2020, 2020 OJ (L 29) 7 [hereinafter Withdrawal Agreement].

² See Gerhard Hafner & Gregor Novak, State Succession in Respect of Treaties, in The Oxford Guide to Treaties 396 (Duncan B. Hollis ed., 2012). The Vienna Convention on Succession of States in Respect of Treaties, Aug. 23, 1978, 1946 UNTS 3, has been in force since 1996, although it only has twenty-three parties. It contains rules regarding “the replacement of one State by another in the responsibility for the international relations of territory.” Id. Art. 2, para. 1(b).

³ The Vienna Convention on the Law of Treaties, May 23, 1969, 1155 UNTS 331 [hereinafter VCLT] applies to constituent instruments of international organizations (Art. 5) and contains rules regarding the termination and suspension of treaties (Arts. 54–64), as does the Vienna Convention on the Law of Treaties Between States and International Organizations or Between International Organizations, Vienna, March 21, 1986 [not in force; hereinafter VCLTIO] in its Articles 54–63. See further Henry G. Schermers & Niels M. Blokker, International Institutional Law: Unity Within Diversity 106–34 (6th ed. 2018) (on the termination of membership and dissolution of international organizations); Helfer, Laurence, Exiting Treaties, 91 Va. L. Rev. 1579, 1582–86 (2005)Google Scholar (summarizing the different motivations states may have for withdrawing from international organizations); and earlier, Akehurst, Michael, Withdrawal from International Organisations, 32 Current Legal Probs. 143 (1979)Google Scholar.

⁴ Catherine Barnard, Introduction: The Constitutional Treaty, the Constitutional Debate and the Constitutional Process, in The Fundamentals of EU Law Revisited: Assessing the Impact of the Constitutional Debate 1, 3 (Catherine Barnard ed., 2007)

⁵ Curtis A. Bradley, What Is Foreign Relations Law?, in The Oxford Handbook of Comparative Foreign Relations Law 3, 3 (Curtis A. Bradley ed., 2019); see also Allan Rosas & Lorna Armati, EU Constitutional Law: An Introduction 14–19 (3d ed. 2018) (summarizing the EU's state-like and non-state-like features).

⁶ Paul McClean, After Brexit: The UK Will Need to Renegotiate at Least 759 Treaties, Fin. Times (May 30, 2017), at https://www.ft.com/content/f1435a8e-372b-11e7-bce4-9023f8c0fd2e.

⁷ See Adam Łazowski & Ramses A. Wessel, The External Dimension of Withdrawal from the European Union, Revue des Affaires européennes 623 (2016); Odermatt, Jed, Brexit and International Law: Disentangling Legal Orders, 31 Emory Int'l L. Rev. 1051 (2017)Google Scholar; Lorand Bartels, The UK's Status in the WTO Post-Brexit, in The United Kingdom and the Federal Idea 227 (Robert Schütze & Stephen Tierney eds., 2018); Wessel, Ramses A., Consequences of Brexit for International Agreements Concluded by the EU and Its Member States, 55 Common Mkt. L. Rev. 101, 124 (2018)Google Scholar; Larik, Joris, The New Transatlantic Trigonometry: “Brexit” and Europe's Treaty Relations with the United States, 40 U. Pa. J. Int'l L. 1 (2018)Google Scholar; Silvereke, Siri, Withdrawal from the EU and Bilateral Free Trade Agreements: Being Divorced Is Worse?, 15 Int'l Orgs. L. Rev. 321, 339 (2018)Google Scholar.

⁸ Richard Partington, Brexit: UK Has Rolled Over Just £16bn Out of £117bn Trade Deals, Guardian (Feb. 13, 2019), at https://www.theguardian.com/business/2019/feb/13/brexit-uk-trade-deals-eu.

⁹ See UK Prime Minister's Office Press Release, Boris Johnson's First Speech as Prime Minister (July 24, 2019), at https://www.gov.uk/government/speeches/boris-johnsons-first-speech-as-prime-minister-24-july-2019 (including a call to “let's start now on those free trade deals” and calling “to recover [the UK's] natural and historic role as an enterprising, outward-looking and truly global Britain”); Daniel Hannan, Brexit Gives Us the Chance to Trade with New and Old Friends, Starting with Japan, Telegraph (Nov. 30, 2019), at https://www.telegraph.co.uk/politics/2019/11/30/brexit-gives-us-chance-trade-new-old-friends-starting-japan; Tim Oliver, Understanding Brexit: A Concise Introduction 67 (2018) (“Vote Leave initially focused on the economic and sovereignty arguments, not least the ability of a non-EU UK to negotiate its own trade deals,” noting that later immigration also assumed an important role in the campaign to leave.).

¹⁰ Joris Larik, Instruments of EU External Action, in EU External Relations Law: Text, Cases and Materials 101, 109 (Ramses A. Wessel & Joris Larik eds., 2020).

¹¹ Treaty Concerning the Accession of the Kingdom of Denmark, Ireland, the Kingdom of Norway and the United Kingdom of Great Britain and Northern Ireland to the European Economic Community and to the European Atomic Energy Community, Brussels, January 22, 1972, 1972 OJ (L 73) 5 (note that Norway, following a referendum rejecting EEC membership, ultimately did not join).

¹² See, e.g., Margaret Thatcher, Speech to Conservative Group for Europe (Opening Conservative Referendum Campaign), Apr. 16, 1975, available at https://www.margaretthatcher.org/document/102675 (noting that leaving the EEC “would be bad for Britain, bad for our relations with the rest of the world and bad for any future treaty on trade we may need to make”).

¹³ Stephen George, An Awkward Partner: Britain in the European Community (3rd ed. 1998); Oliver,supra note 9, at 39–44.

¹⁴ Finn Laursen, Hans Mouritzen & Anders Wivel, The Institutional Dynamics of Euro-Atlantic Integration, in The Geopolitics of Euro-Atlantic Integration 39, 44 (Hans Mouritzen & Anders Wivel eds., 2005).

¹⁵ See David Gowland, Britain and the European Union 219–30 (2016).

¹⁶ See The UK Challenge to Europeanization: The Persistence of British Euroscepticism (Karine Tournier-Sol & Chris Gifford eds., 2015).

¹⁷ Kenneth Armstrong, Brexit Time: Leaving the EU – Why, How and When? 42 (2017).

¹⁸ A New Settlement for the United Kingdom Within the European Union, Extract of the Conclusions of the European Council of 18–19 February 2016, 2016 OJ (C 69I) 1.

¹⁹ UK Electoral Commission, Results and turnout at the EU referendum (last updated September 25, 2019), at https://www.electoralcommission.org.uk/who-we-are-and-what-we-do/elections-and-referendums/past-elections-and-referendums/eu-referendum/results-and-turnout-eu-referendum.

²⁰ Consolidated Version of the Treaty on European Union, 2016 OJ (C 202) 13, Art. 50, para. 2 [hereinafter TEU]; see in detail on the process, Paul Craig, The Process: Brexit and the Anatomy of Article 50, in The Law & Politics of Brexit 49 (Federico Fabbrini ed., 2017).

²¹ R (on the Application of Miller and Another) (Respondents) v. Secretary of State for Exiting the European Union (Appellant), [2017] UKSC 5, para. 101.

²² TEU, supra note 20, Art. 50, para. 3.

²³ Kevin O'Rourke, A Short History of Brexit: From Brentry to Backstop, ch. 11 (2019).

²⁴ Barnier: Brexit Deal Negotiations Like Climbing a Mountain, BBC News (Oct. 11, 2019), at https://www.bbc.com/news/uk-politics-50007206.

²⁵ Agreement on the Withdrawal of the United Kingdom of Great Britain and Northern Ireland from the European Union and the European Atomic Energy Community, 2019 OJ (C 144I) 1.

²⁶ Max Colchester & Jason Douglas, May's Brexit Deal Is Rejected for a Third Time by Lawmakers, Wall St. J. (Mar. 29, 2019), at https://www.wsj.com/articles/mays-brexit-deal-is-rejected-for-a-third-time-by-lawmakers-11553870628.

²⁷ Heather Stewart, Brexit: MPs Pass Withdrawal Agreement Bill by 124 Majority, Guardian (Dec. 20, 2019), at https://www.theguardian.com/politics/2019/dec/20/brexit-pm-asks-britons-to-move-on-as-mps-debate-withdrawal-bill.

²⁸ European Council Decision (EU) 2019/1810 Taken in Agreement with the United Kingdom of 29 October 2019 Extending the Period Under Article 50(3) TEU, 2019 OJ (L 278I) 1, Art. 1.

²⁹ Revised Protocol on Ireland and Northern Ireland Included in the Withdrawal Agreement, Oct. 17, 2019, TF50 64 (2019) – Commission to EU 27 [hereinafter Northern Ireland Protocol].

³⁰ Jennifer Rankin, Why Ireland Is Biggest Stumbling Block in Reaching a Brexit Deal, Guardian (Sept. 17, 2018), at https://www.theguardian.com/politics/2018/sep/17/brexit-why-ireland-biggest-stumbling-block-deal.

³¹ Northern Ireland Protocol, supra note 29, Art. 4, para. 1.

³² Id. Art. 5, para. 4, Annex 2.

³³ Id. Art. 5, para. 1.

³⁴ Id. Art. 18, para. 5.

³⁵ Id. Art. 18, paras. 5–6.

³⁶ See Łazowski & Wessel, supra note 7.

³⁷ McClean, supra note 6.

³⁸ European Council, Draft Guidelines Following the United Kingdom's Notification Under Article 50 TEU, para. 13, XT 21001 (Mar. 31, 2017).

³⁹ UK Department for International Trade, Preparing for Our Future UK Trade, Cm 9470, 27 (Oct. 2017).

⁴⁰ Silvereke, supra note 7, at 339; Odermatt, supra note 7, at 1056.

⁴¹ Joni Heliskoski, Mixed Agreements as a Technique for Organizing the International Relations of the European Community and Its Member States 7 (2001).

⁴² Robert Schütze, Federalism and Foreign Affairs: Mixity as an (Inter)national Phenomenon, in Mixed Agreements Revisited: The EU and Its Member States in the World 57, 71–72 (Christophe Hillion & Panos Koutrakos eds., 2010) (using Belgium as an example of a federation that concluded mixed agreements with other countries).

⁴³ Bartels, supra note 7, at 229–32; Wessel, supra note 7, at 124.

⁴⁴ See UK Government, Communication to WTO Members Following the UK's Withdrawal from the EU, pt. 1.1 (Feb. 1, 20) (“The United Kingdom has been, and will continue to be, a Member of the World Trade Organization and will represent its interests and uphold its obligations on that basis from that date.”).

⁴⁵ Silvereke, supra note 7, at 340.

⁴⁶ Wessel, supra note 7, at 120; Odermatt, supra note 7, at 1059–60; Giorgio Sacerdoti, The Prospects: The UK Trade Regime with the EU and the World: Options and Constraints Post-Brexit, in The Law & Politics of Brexit 71, 82 (Federico Fabbrini ed., 2017).

⁴⁷ VCLT, supra note 3, Art. 39; VCLTIO, supra note 3, Art. 39. The rules regarding the amendment of multilateral treaties between all or some of its parties are not applicable here since these mixed agreements are in essence bilateral. Only through amendment would they be turned into multilateral ones.

⁴⁸ This is the case, for example, with the trade agreement with the Republic of Korea. The Free Trade Agreement Between the European Union and Its Member States, of the One Part, and the Republic of Korea, of the Other Part, 2011 OJ (L 127) 6, is a mixed agreement that includes the EU member states as parties. The UK has signed a continuity agreement with that country to replace this agreement in June 2019. See Julia Kollewe, UK and South Korea Agree to Sign Post-Brexit Trade Deal, Guardian (June 10, 2019), at https://www.theguardian.com/business/2019/jun/10/uk-south-korea-brexit-trade-deal-asia-eu.

⁴⁹ Rowena Mason, Britain “Shackled to Corpse” of EU, Says Douglas Carswell, Telegraph (Oct. 26, 2012), at https://www.telegraph.co.uk/news/politics/9636417/Britain-shackled-to-corpse-of-EU-says-Douglas-Carswell.html.

⁵⁰ Id.

⁵¹ David Davis, Britain Would Be Better Off Out of the EU – and Here's Why, ConservativeHome (Feb. 4, 2016), at https://www.conservativehome.com/platform/2016/02/david-davis-britain-would-be-better-off-out-of-the-eu-and-heres-why.html.

⁵² UK House of Commons, Hansard, Business of the House (Saturday 19 October), Vol. 666, col. 490 (Oct. 17, 2019), at https://hansard.parliament.uk/Commons/2019-10-17/debates/C7D5E220-3549-4DF1-AF9E-07079573464C/BusinessOfTheHouse(Saturday19October).

⁵³ UK Department for International Trade, supra note 39, at 26 (“The Commonwealth is home to a third of the world's population, many of its fastest growing economies, and half of the globe's top 20 emerging cities. This vast network of growing markets, with which the UK has long-established relationships, presents a significant opportunity for UK business and enhances the UK's ability to promote free trade in a multilateral rules-based system.”).

⁵⁴ See, e.g., Benjamin Oreskes & Victoria Guida, The Bright Side of Brexit? A U.S.-UK Trade Deal, Politico (June 24, 2016), at https://www.politico.com/story/2016/06/brexit-us-britain-trade-deal-224776.

⁵⁵ European Commission, Trade for All: Towards a More Responsible Trade and Investment Policy 7 (2015).

⁵⁶ Guy Verhofstadt, Boris Johnson's Talk of “Global Britain” Is About to Look Even More Ridiculous, Guardian (June 27, 2019), at https://www.theguardian.com/commentisfree/2019/jun/27/boris-johnson-global-britain-eu-trade-deal.

⁵⁷ Id.

⁵⁸ Case C–621/18, Wightman v. Secretary of State for Exiting the European Union, ECLI:EU:C:2018:999, para. 74.

⁵⁹ Dirk Hanschel, Konfliktlösung im Bundesstaat 76–79 (2012).

⁶⁰ See Robert Schütze, Foreign Affairs Federalism in the European Union, in The Oxford Handbook of Comparative Foreign Relations Law, supra note 5, at 333.

⁶¹ Consolidated Version of the Treaty on the Functioning of the European Union, 2016 OJ (C 202) 1, Art. 3, para. 1 [hereinafter TFEU].

⁶² Id. Art. 3, para. 1(e).

⁶³ The principle of preemption was first established in Case 22/70 Commission v. Council (ERTA) [1971] ECR 263 and later largely codified in TFEU, Art. 3, para. 2: “The Union shall also have exclusive competence for the conclusion of an international agreement . . . in so far as its conclusion may affect common rules or alter their scope.”

⁶⁴ TEU, supra note 20, Art. 4, para 3(3).

⁶⁵ See, in particular, Case C-246/07 Commission v. Sweden (PFOS), ECLI:EU:C:2010:203, para. 91, in which the Court found that “the Kingdom of Sweden [had] dissociated itself from a concerted common strategy within the Council” with regard to an international environmental agreement and had, therefore, violated its duty of cooperation. See Peter van Elsuwege, The Duty of Sincere Cooperation and Its Implications for Autonomous Member State Action in the Field of External Relations, in Between Compliance and Particularism: Member State Interests and European Union Law 283 (Marton Varju ed., 2019); Andrés Delgado Casteleiro & Larik, Joris, The Duty to Remain Silent: Limitless Loyalty in EU External Relations?, 36 Eur. L. Rev. 522 (2011)Google Scholar.

⁶⁶ UK Department for International Trade Press Release, US-UK Trade Working Group Lays Groundwork for Potential Future Trade Agreement (July 25, 2017), at https://www.gov.uk/government/news/us-uk-trade-working-group-lays-groundwork-for-potential-future-free-trade-agreement.

⁶⁷ While the VCLT and VCLTIO do not contain a definition of “negotiations,” Valerio De Oliveira Mazzuoli, The Law of Treaties: A Comprehensive Study of the 1969 Vienna Convention and Beyond 89 (2016) concludes that negotiations for the purposes of the law of treaties have started “when the representatives of States meet at a specific place and at arranged time, for the purpose of studying the possibilities to reach an agreement in connection with the conclusion of a specific international instrument in a joint manner.”

⁶⁸ Theresa May: UK Will Lead World in Free Trade, BBC News (Sept. 7, 2016), at http://www.bbc.com/news/uk-politics-37291832.

⁶⁹ Kollewe, supra note 48.

⁷⁰ Larik, Joris, Sincere Cooperation in the Common Commercial Policy: Lisbon, a “Joined-Up” Union, and “Brexit,” 8 Eur. Y.B. Int'l Econ. L. 83, 103 (2017)Google Scholar; Wessel, supra note 7, at 112.

⁷¹ UK Department for International Trade Press Release, UK Trade with Trade Agreement Continuity (TAC) Countries: Statistical Ad Hoc Release (Updated Dec. 4, 2019), at https://www.gov.uk/government/publications/uk-trade-agreement-continuity-statistics-and-analysis/uk-trade-with-trade-agreement-continuity-tac-countries-statistical-ad-hoc-release. Note that this “excludes Turkey, San Marino and Andorra, which are part of a customs union with the EU, and excludes Japan, as the economic partnership agreement only came into force on 1 February 2019.” See also Tom Edington, Brexit: What Trade Deals Has the UK Done so Far?, BBC News (Mar. 2, 2020), at https://www.bbc.com/news/uk-47213842.

⁷² Edington, supra note 71.

⁷³ These are the Andean countries, the CARIFORUM trade bloc, the Central America group, the Eastern and Southern Africa (ESA) trade bloc, Iceland and Norway, the Pacific states group, and the Southern Africa Customs Union and Mozambique (SACU+M) trade bloc.

⁷⁴ UK Department for International Trade Press Release, Existing UK Trade Agreements with Non-EU Countries (Jan. 29, 2020), at https://www.gov.uk/guidance/uk-trade-agreements-with-non-eu-countries.

⁷⁵ Free Trade Agreement Between the United Kingdom of Great Britain and Northern Ireland and the Republic of Korea (with Exchange of Notes), Art. 15.10, para. 1, London, Aug. 22, 2019 (not currently in force); Agreement Establishing an Association Between the United Kingdom of Great Britain and Northern Ireland and the Republic of Chile, Art. 10, para. 3(a)(i), Santiago, Jan. 30, 2019. An exception to this pattern is the UK's agreement with Norway and Iceland regarding trade in goods, which would only have entered into force if the UK had withdrawn from the EU “without any agreement between the United Kingdom and the European Union on the terms of the United Kingdom's withdrawal” or if the Withdrawal Agreement had not provided “for the continued application to the United Kingdom of the Trade-Related Agreements between the European Union and one or both of Iceland and Norway in respect of trade in goods,” Agreement Between the United Kingdom of Great Britain and Northern Ireland, Iceland and the Kingdom of Norway on Trade in Goods, Art. 17, para. 2, London, April 2, 2019 (not in force). The author thanks Holger Hestermeyer for the latter point.

⁷⁶ UK Department for International Trade Press Release, Continuing the United Kingdom's Trade Relationship with The Faroe Islands 4 (Feb. 2019), available at https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/777022/continuing-the-uks-trade-relationship-with-the-faroe-islands.pdf.

⁷⁷ See, e.g., Agreement Establishing an Association Between the United Kingdom of Great Britain and Northern Ireland and the Republic of Chile, supra note 75, Art. 3, para. 1.

⁷⁸ Id.; Trade and Partnership Agreement Between the Government of the United Kingdom of Great Britain and Northern Ireland and the Government of the State of Israel, Tel Aviv, Feb. 18, 2019.

⁷⁹ Free Trade Agreement Between the United Kingdom of Great Britain and Northern Ireland and the Republic of Korea, supra note 75; Economic Partnership Agreement Between the Southern African Customs Union Member States and Mozambique, of the One Part, and the United Kingdom of Great Britain and Northern Ireland, of the Other Part, London, Oct. 9, 2019 (not currently in force).

⁸⁰ For example, in terms of the institutional framework to be established by the agreement, it is specified that instead of representatives from the EU, the “Association Council shall be composed, on the one hand, of a Secretary of State of the United Kingdom or their representative(s), and, on the other hand, of the Minister of Foreign Affairs of Chile.” Agreement Establishing an Association Between the United Kingdom of Great Britain and Northern Ireland and the Republic of Chile, supra note 75, Annex, sec. 1.

⁸¹ Id.; Annex, sec. 5 regarding the UK's tariff elimination schedule, including tariff quotas.

⁸² Free Trade Agreement Between the United Kingdom of Great Britain and Northern Ireland and the Republic of Korea, supra note 75, Art. 1.3, para. 2.

⁸³ Marise Cremona, Negotiating Trade Deals Before Brexit?, Social Europe (July 25, 2016), at https://www.socialeurope.eu/negotiating-trade-deals-brexit.

⁸⁴ Id.

⁸⁵ Streinz, Thomas, Cooperative Brexit: Giving Back Control Over Trade Policy, 15 Int'l J. Constitutional L. 271 (2017)Google Scholar.

⁸⁶ TFEU, supra note 61, Art. 2, para. 1 (“When the Treaties confer on the Union exclusive competence in a specific area, only the Union may legislate and adopt legally binding acts, the Member States being able to do so themselves only if so empowered by the Union or for the implementation of Union acts” (emphasis added).).

⁸⁷ TFEU, supra note 61, Art. 258.

⁸⁸ Nonetheless, the European Commission brought infringement proceedings against the UK on other matters during period of the withdrawal negotiations. See, for example, this application regarding the EU's value added tax directive, Case C-276/19, European Commission v. United Kingdom, Action Brought on April 1, 2019, 2019 OJ (C 206) 35.

⁸⁹ Nicolo Tamberi & L. Alan Winter, The UK's Continuity Trade Agreements: Is the Roll-Over Complete?, UK Trade Pol'y Observatory (Mar. 29, 2019), at https://blogs.sussex.ac.uk/uktpo/2019/03/29/the-uks-continuity-trade-agreements-is-the-roll-over-complete.

⁹⁰ Marise Cremona, UK Trade Policy, in The UK After Brexit: Legal and Policy Challenges 247, 259 (Michael Dougan ed., 2017).

⁹¹ According to the UK government, discussions with these and other countries are ongoing at the time of writing. UK Department for International Trade, supra note 74.

⁹² Trade Agreement Between the United Kingdom of Great Britain and Northern Ireland and the Swiss Confederation, Art. 1, para. 1(e), Bern, Feb. 11, 2019 (not currently in force).

⁹³ Id. Art. 2.

⁹⁴ Swiss Federal Government, Economic Relations Between Switzerland and the United Kingdom After Brexit (as of 29.03.2019), E-Informationsdossier, 6.

⁹⁵ Id. at 8.

⁹⁶ UK Department for Exiting the European Union, Implementation Period, fact sheet (2019).

⁹⁷ Withdrawal Agreement, supra note 1, Art. 126.

⁹⁸ Id. Art. 132, para. 1.

⁹⁹ Oliver,supra note 9, 66.

¹⁰⁰ Withdrawal Agreement, supra note 1, Art. 127, para. 1: “Unless otherwise provided in this Agreement, Union law shall be applicable to and in the United Kingdom during the transition period.” Id. Art. 131, para. 1: “In particular, the Court of Justice of the European Union shall have jurisdiction as provided for in the [EU] Treaties.”

¹⁰¹ Id. Art. 7, para. 1.

¹⁰² Id. Art. 129, para. 1.

¹⁰³ Id. Art. 129, para. 2.

¹⁰⁴ Id. Art. 129, para. 3.

¹⁰⁵ Id. Art. 185, para. 4.

¹⁰⁶ See notes 64–65 supra and accompanying text.

¹⁰⁷ Withdrawal Agreement, supra note 1, Art. 129, para. 1, n. 1.

¹⁰⁸ At least according to the Vienna Convention on Succession of States in respect of Treaties, supra note 2, Art. 34, para. 1, “[w]hen a part or parts of the territory of a State separate to form one or more States, . . . (a) any treaty in force at the date of the succession of States in respect of the entire territory of the predecessor State continues in force in respect of each successor State so formed.”

¹⁰⁹ VCLT, supra note 3, Art. 34; VCLTIO, supra note 3, Art. 34.

¹¹⁰ Withdrawal Agreement, supra note 1, Art. 129, para. 1, n. 1.

¹¹¹ Id. Art. 129, para. 4.

¹¹² Id. Art. 158.

¹¹³ Id. Art. 168.

¹¹⁴ Id. Art. 170.

¹¹⁵ Id. Art. 174, para. 1. Such CJEU rulings can also be requested by either party by making submissions to the arbitration panel (Id. Art. 174, para. 2).

¹¹⁶ Political Declaration Setting Out the Framework for the Future Relationship Between the European Union and the United Kingdom, pt. 23, Nov. 22, 2018, XT 21095/18.

¹¹⁷ Allie Renison, Understanding Brexit: How the “Backstop” Became the “Frontstop,” Prospect Mag. (Oct. 18, 2019), at https://www.prospectmagazine.co.uk/economics-and-finance/understanding-brexit-how-the-backstop-became-the-frontstop-northern-ireland.

¹¹⁸ See notes 32–35 supra and accompanying text.

¹¹⁹ Revised Text of The Political Declaration Setting Out the Framework for the Future Relationship Between the European Union and the United Kingdom as Agreed at Negotiators’ Level on 17 October 2019, TF5065, pt. 3, (2019).

¹²⁰ HM Government, The Future Relationship with the EU: The UK's Approach to Negotiations, CP 2020, pt. 2 (Feb. 2020).

¹²¹ Id. pt. 5.

¹²² Comprehensive Economic and Trade Agreement (CETA) Between Canada, of the One Part, and the European Union and Its Member States, of the Other Part, 2017 OJ (L 11) (not in force; partial provisional application).

¹²³ Id. pts. 6–7.

¹²⁴ Framework Agreement Between the European Union and Its Member States, of the One Part, and Australia, of the Other Part, 2017 OJ (L 237) 7; and, for example, Agreement Between the European Union and Australia Amending the Agreement on Mutual Recognition in Relation to Conformity Assessment, Certificates and Markings Between the European Community and Australia, 2012 OJ (L 359) 2.

¹²⁵ Council Decision Authorising the Opening of Negotiations with the United Kingdom of Great Britain and Northern Ireland for a New Partnership Agreement, Addendum: Directives for the Negotiation of a New Partnership with the United Kingdom of Great Britain and Northern Ireland, Feb. 25, 2020, 5870/20 ADD 1 Rev 3, pt. 19.

¹²⁶ Id. pt. 158.

¹²⁷ Id. pt. 160.

¹²⁸ Comprehensive Economic and Trade Agreement (CETA), supra note 122, Arts. 8.9, 23.2, 24.3.

¹²⁹ Revised Text of the Political Declaration, supra note 119, pt. 18 (stating that the “Parties will retain their autonomy and the ability to regulate economic activity according to the levels of protection each deems appropriate in order to achieve legitimate public policy objectives . . .”).

¹³⁰ Richard Partington, Trump Adviser Ross Says UK-US Trade Deal Will Mean Scrapping EU Rules, Guardian (Nov. 6, 2017), at https://www.theguardian.com/business/2017/nov/06/trump-ross-says-uk-us-trade-deal-eu-brexit-chlorinated-chicken.

¹³¹ Anu Bradford, The Brussels Effect: How the European Union Rules the World (2020).

¹³² Edington, supra note 71.

¹³³ Craig, supra note 20, at 69 (noting “the fact that a comprehensive trade agreement will require lengthy discussion”).

¹³⁴ Sacerdoti, supra note 46, at 77–78.

¹³⁵ Larik, Joris, EU External Relations Law and Brexit: “When Pluto Was a Planet,” 4 Eur. & World: L. Rev. 1, 12–17 (2020)Google Scholar (summarizing the EU's new practice of splitting up ambitious trade agreements in a way that avoids the need for ratification by the member states).