1 “Zeppelin” was the generic name given to all German airships. Similarly, the name “Dicke Bertha”, or “Big Bertha”, was used not just for the 420-mm howitzer from the Krupp factories, but also (incorrectly) to describe all long-range cannons, including the Pariser Kanonen that bombarded Paris in 1918. “U-boot” was an abbreviation of Unterseeboot, which means submarine in German, and “spy mania” was the neologism coined during the Great War to describe the paranoia of those who thought they saw spies everywhere.

2 The aim sought was not so much military and local (tactical) as political and global (strategic): to undermine the morale of the civilian population at the rear, and push the government to negotiate.

3 Marin, G., “L'espionnage par T.S.F.”,  Lectures pour tous, January 1923, pp. 516–518 Google Scholar.

4 I am deliberately using the wording of Article 36 of the Protocol Additional (I) to the Geneva Conventions of 12 August 1949, and Relating to the Protection of Victims of International Armed Conflicts, 1125 UNTS 3, 8 June 1977 (entered into force 7 December 1978), on new weapons, which binds the contracting nations to verify that “a new weapon, means or method of warfare” complies with international law.

5 The crossbow is the most famous historical example of the moral issues raised by a long-distance weapon since its use (against Christians) has been forbidden under penalty of anathema by Pope Innocent II at the Second Lateran council in 1139. It had been re-invented in winter 1914 to be used as a soundless grenade launcher to “treacherously” hit soldiers of the opposite trench. This photograph of a crossbow “Letellier” presented to the chief of staff of the French Fifth Army was taken by a young Major, Louis Gousseau, great grandfather of the author, Éric Germain.

6 In March 2003, President George W. Bush created a “Global War on Terrorism Expeditionary Medal”.

7 Among them the Fellowship of Reconciliation (FoR), an NGO founded in England in December 1914, which has condemned the “virtualization” of warfare using drones. FoR, Convenient Killing: Armed Drones and the “PlayStation mentality”, Oxford, September 2010, available at: http://dronewarsuk.files.wordpress.com/2010/10/conv-killing-final.pdf (all online references were accessed in September 2016). The operator of a drone or a “cyberweapon” is at an obvious physical distance, but the same is also true of a special forces soldier on certain missions (e.g. a sniper).

8 Christopher Paul, Isaac Porche and Elliot Axelband, The Other Quiet Professionals: Lessons for Future Cyber Forces from the Evolution of Special Forces, RAND Corporation, Santa Monica, CA, 3 October 2014, cf. “Lessons from the Analogy”, pp. 42–46, available at: www.rand.org/t/rr780.html.

9 Éric Germain, “L'ennemi… Toujours plus loin”, 1914–2014: Un siècle de guerre, Le Monde, October–December 2013, p. 31. Charles Guynemer moved in high-society circles with the actress Yvonne Printemps. By the time of his death, on 11 September 1917, the French flying ace had achieved a total of fifty-three officially recognized victories.

10 The American biologist Paul Bingham goes a good deal further, presenting this ability to kill or injure other human beings from a distance as the main force driving the evolution of the human species towards “cooperative social adaptation” (to the extent that, as he puts it, the ability to kill remotely dramatically reduces “the individual cost of punishing non-cooperative behaviour by allowing these costs to be distributed among multiple cooperators”); Bingham, P.M., “Human Uniqueness: A General Theory”, Quarterly Review of Biology, Vol. 74, No. 2, June 1999, pp. 133–169 CrossRefGoogle Scholar.

11 The fighter planes had been sent to fly over Paris in order to reconnoitre. “Le cannon qui bombarda Paris” (The cannon that bombed Paris), Les Cannons de l'apocalypse, 19 August 2001, available at: http://html2.free.fr/cannons/canparis.htm. The Pariser Kanonen were initially confused with Big Berthas.

12 They could reach a maximum altitude of some forty kilometres, and had a theoretical range of 130 kilometres. Huyon, Alain, “La Grosse Bertha des Parisiens – Historique d'une arme de légende”, Revue historique des armées, No. 253, 2008, pp. 111–125, note 9Google Scholar, available at : https://rha.revues.org/4682.

13 Although placed on the agenda for the conference, the banning of submarines was quickly dismissed. Levie, Howard S., “Submarine Warfare: With Emphasis on the 1936 London Protocol”, in Schmitt, Michael N. and Green, Leslie C. (eds), International Law Studies: Levie on the Law of War, Vol. 70, 1998, pp. 294–295 Google Scholar.

14 At first, some States suspected this was a Russian manoeuvre to offset the backwardness of their defence industry. They quickly became convinced of the sincerity of the Tsar, who was following in the Romanov tradition of military ethics (as exemplified by the 1804 initiative of Alexander I, who proposed to the British Prime Minister a system for the peaceful settlement of conflicts and a declaration designed to ban the use of certain projectiles in time of war (Saint Petersburg Declaration), 29 November–11 December 1868).

15 French Ministry of Foreign Affairs, Documents Diplomatiques. Conférence Internationale de la Paix, 1899, Imprimerie nationale, Paris, p. 4, available at: http://gallica.bnf.fr/ark:/12148/bpt6k56137625/f13.image. The final act of the conference was signed on 29 July 1899 by twenty-seven nations, most of whom were belligerents in the First World War.

16 Ibid ., p. 5. The first really motorized, manoeuvrable aerostat (“dirigible”, balloon or airship) was designed in 1884, but the first motorized aircraft (heavier than air) did not appear until the very beginning of the twentieth century.

17 List of States party to Declaration (IV, 1), to Prohibit, for the Term of Five Years, the Launching of Projectiles and Explosives from Balloons, and Other Methods of Similar Nature, The Hague, 29 July 1899, available at: https://www.icrc.org/applic/ihl/ihl.nsf/States.xsp?xp_viewStates=XPages_NORMStatesParties&xp_treatySelected=160.

18 List of States signatory to Declaration (IV, 1), The Hague, 29 July 1899, available at: https://www.icrc.org/applic/ihl/ihl.nsf/States.xsp?xp_viewStates=XPages_NORMStatesSign&xp_treatySelected=160.

19 List of States Partis to Declaration (XIV) Prohibiting the Discharge of Projectiles and Explosives from Balloons, The Hague, 18 October 1907, available at: https://www.icrc.org/ihl/INTRO/245?OpenDocument.

20 List of signatory States to Declaration (XIV), The Hague, 18 October 1907, available at: https://www.icrc.org/applic/ihl/dih.nsf/States.xsp?xp_viewStates=XPages_NORMStatesSign&xp_treatySelected=245.

21 According to Article 25 of Hague Convention (II) with Respect to the Laws and Customs of War on Land and its annex: Regulations concerning the Laws and Customs of War on Land, the Hague, 29 July 1899, “The attack or bombardment of towns, villages, habitations or buildings which are not defended, is prohibited”. Hague Convention II, 29 July 1899, entered into force on 4 September 1900. Available at: https://www.icrc.org/applic/ihl/ihl.nsf/Article.xsp?action=openDocument&documentId=88354A9664EEA72FC12563CD00515E46.

22 H.G. Wells, The War in the Air, George Bell and Sons, London, 1908. This subject also recurred in many other books at the time, including Aerial Warfare by Hearne, R.P., John Lane, London and New York, 1909 Google Scholar.

23 Grant, R.G. (ed.), Flight: 100 Years of Aviation, Dorling Kindersley Publishing, Inc., London, 2004, p. 59Google Scholar.

24 Ross, Stewart H., Strategic Bombing by the United States in World War II: The Myths and the Facts, McFarland & Company, Jefferson, NC, 2003, p. 20Google Scholar.

25 Ibid ., p. 18, quoting the Rear Admiral Paul Behncke, deputy chief of the German Naval Staff.

26 For these altitudes, crews were equipped with respiratory masks attached to bottles of oxygen.

27 Statement by the First Lord on 6 April 1900 in the House of Commons, quoted by Paul Akermann, Encyclopaedia of Bristish Submarines 1901–1955, 1989, p. 112.

28 In 1901 Admiral Arthur Wilson, Controller of the Royal Navy, declared that underwater warfare was “underhand, unfair and damned un-English”. He went so far as to threaten to hang any captured submariner like a pirate. “Royal Navy Submarine Service – History”, available at: http://www.royal-navy.org/node/7.

29 In 1914 the Royal Navy had fifteen submarines capable of missions on the high seas, while the German fleet had fourteen. “The First World War 1914–1918”, in “Most Dangerous Service”: A Century of Royal Navy Submarines, available at: http://archive.iwm.org.uk/upload/package/12/submarines/ww1.htm and Hans J. Koerver (ed.), German Submarine Warfare 1914–1918 in the Eyes of British Intelligence: Selected Sources from the British National Archives, Kew, 2012, LIS Reinisch, Steinbach, p. xvii.

30 In 1915, and especially from 1917 onwards, the Reichsmarine had decided to torpedo civilian ships without first searching them or checking the conditions for rescuing passengers and crew members. This violated existing customs underpinning maritime law.

31 Wilson, David A. H., “Avian anti-submarine warfare proposals in Britain, 1915–18: The Admiralty and Thomas Mills”, International Journal of Naval History, Vol. 5, No. 1, April 2006, p. 8Google Scholar.

32 “Genèse de la DCA française”, in Base documentaire Artillery-BAS'ART, available at: http://basart.artillery.asso.fr/article.php3?id_article=738.

33 Saibène, Marc, “La lutte anti-sous-marine, 1939–1940”, Marines, Guerre & Commerce, No. 62, August–September 1999, pp. 35–39 Google Scholar; Claude Gazanhes, “Du laboratoire de la guerre sous-marine de Toulon au laboratoire de mécanique et d'acoustique de Marseille”, La revue pour l'histoire du CNRS, February 2000, available at: http://histoire-cnrs.revues.org/2772.

34 There was the invention by the soldier Ferdinand Daussy (Hubert Saur and Henri Tribout de Morembert, “Ferdinand Daussy”, Académie nationale de Metz, 1968, available at: http://documents.irevues.inist.fr/handle/2042/34140), the devices invented by the physicists Alexandre Dufour, Pierre Weiss and Aimé Cotton, and the one developed by the engineer Ludovic Driencourt in collaboration with Gustave Ferrié. Pierre Lamandé, Rapport Science-Industrie-États: L'impact de la Première Guerre mondiale, Report, Nantes University, 2009, p. 15, available at: http://foad.refer.org/IMG/pdf/AUF-cours_UEF2.pdf.

35 Émile-August Chartier (Alain), Souvenirs de guerre (Memories of War), Paul Hartmann, Paris, 1937 Google Scholar, republished in Bénézé, Georges (ed.), Les Passions et la sagesse, Bibliothèque de la Pléiade, Paris, 1960, p. 476Google Scholar.

36 Ibid ., p. 495. Lieutenant-Colonel Gustave Ferrié had built a model of a mobile wireless telegraphy unit, over 12,000 of which were to equip the allied armies between 1914 and 1918. P. Lamandé, above note 34, p. 13.

37 Émile-August Chartier (Alain), Mars ou la guerre jugée, Éditions Gallimard, Paris, 2nd ed., 1936, p. 205Google Scholar. (English edition published under the title Mars; Or the Truth about War, New York, Jonathan Cape & Harrison Smith N.D., 1930).

38 Apollinaire, Guillaume, Lettres à Madeleine (Letters to Madeleine), Campa, Laurence (ed.), Gallimard, Paris, 2005 Google Scholar, letter of 2 December 1915, p. 363. In his Souvenirs de guerre, Alain confirms this feeling of inequality (above note 35, p. 447), although in another text he puts this “immunity” into perspective by recalling the heavy losses suffered by artillerymen in the Battle of the Marne. É. Chartier, above note 37, p. 117.

39 In the trenches, fewer wounds were inflicted by direct fire than by shrapnel. At the end of 1914 the French army distributed a metal skull cap, known as a cervelière (brain-cap), to reinforce the képi.

40 In September 1915 the “Adrian” steel helmet was distributed to the troops en masse. Its equivalents, the German Stahlhelm and British Brodie helmet, appeared the following year. Details of the Adrian helmet may be found on the World War Helmets website at: http://www.world-war-helmets.com/fiche.php?q=Casque-Francais-Adrian-Mle-15.

41 Ibid . This was particularly true of the facial protection that adapted the Adrian helmet and transformed it into a kind of barrel helm, and of the breastplates that gave protection from howitzers’ shrapnel (like the German Sappenpanzer, which could be worn either on a foot soldier's chest or on his back).

42 The Italian ace Francesco Baracca who, on 7 April 1916, flew down to shake hands with an Austrian pilot forced to land, exemplifies these elegant gestures, to be found in each camp. Georges Pagé, L'aviation française 1914–1918, Grancher, Paris, 2011, Ch. 33.

43 Although this decision was also a tactic whereby his squadron remained hidden, under cloud cover – the better to swoop on an adversary absorbed in the combat he had initiated.

44 This was done in mid-September 1916. Morrow, John H., “Les airs”, in Winter, Jay (ed.), La Première Guerre mondiale – tome 1: Combats, Fayard, Paris, 2013, p. 397Google Scholar.

45 Such as the dropping of bombs by a French plane on the Zeppelin hangars in the Metz-Frescaty base, on 14 August 1914. Daçay, Jean, “Celui qui survola le premier les hangars de Frescati”, La Guerre Aérienne Illustrée (Paris), Vol. 21, No. A1, 5 April 1917, pp. 330–331 Google Scholar, available at: http://gallica.bnf.fr/ark:/12148/bpt6k6246433d/f1.image.

46 Neumann, Georg P. (ed.), In der Luft unbesiegt: Erlebnisse im Weltkrig (Undefeated in the Air: Experiences of the World War), Lehmanns, Munich, 1923; quoted by Morrow, J.H., above note 44, pp. 403–404 Google Scholar.

47 J.H. Morrow, above note 44, 2013, p. 411. This argument may be compared with that put forward by Rear Admiral Paul Behncke, deputy chief of the German Naval Staff who said in August 1914 that the proposed attacks “may be expected, whether they involve London or the neighbourhood of London, to cause a panic in the population which may possibly render it doubtful that the war can be continued”; quoted by S. Ross, above note 24, 2003, p. 18, note 7.

48 Harvey A. DeWeerd, President Wilson Fights His War: World War I and the American Intervention, Macmillan, New York, 1968, p. xx, quoted in Wilms, Wilfried, “Hollywood's Celluloid Air War”, in Wilms, W. & Rasch, W. (eds), Bombs Away! Representing the Air War Over Europe and Japan, Amsterdamer Beiträge zur neueren Germanistik, Amsterdam, Rodopi, Vol. 60 (2006), p. 360Google Scholar.

49 See the article “War”, The Straits Times, 29 May 1915, p. 10, and the report in L’Aérophile, 1–15 June 1915, available at: http://gallica.bnf.fr/ark:/12148/bpt6k6553361f/texteBrut.

50 Cartoon printed with the caption “Wilfully Stupid” in How did London civilians respond to the German airship raids of 1915?, available at: http://www.londonairshipraids1915.co.uk/introduction.htm.

51 The use of such projectiles was regarded as “contrary to the laws of humanity”, as these weapons would “uselessly aggravate the sufferings of disabled men, or render their death inevitable”. Declaration Renouncing the Use, in Time of War, of certain Explosive Projectiles (St Petersburg Declaration), Saint Petersburg, 29 November/11 December 1868, Preamble, available at: https://www.icrc.org/applic/ihl/ihl.nsf/ART/130-60001?OpenDocument&xp_articleSelected=60001.

52 Norman Archibald, Heaven High, Hell Deep: 1917–1918, A. C. Boni, Inc., New York, 1935, p. 186.

53 Ibid ., pp. 186–187.

54 H. Gorsse and P. Guitet-Vauquelin, L’aéroplane invisible, Hachette, Paris, 1921.

55 During the Second World War a similar ethical justification underpinned American General “Hap” Arnold's plan to turn bombers into drones so they could be sent to explode over German submarine bases. Sarah Kreps and Micah Zenko, “The Next Drone Wars: Preparing for Proliferation”, in Foreign Affairs, March–April 2014, available at: http://www.foreignaffairs.com/articles/140746/sarah-kreps-and-micah-zenko/the-next-drone-wars.

56 Regardless of whether the aircraft's “stealth” was the result of high altitude, a night flight or, as in this novel for young people, the invention of new camouflage technology such as the clear dope covering the wings and fuselage of the German Taube bomber, “making it almost transparent against a bright sky”. Marshall Michel, “Stealth, 1914 style”, available at: http://www.kaiserslauternamerican.com/stealth-1914-style/.

57 Rules concerning the Control of Wireless Telegraphy in Time of War and Air Warfare, Part II: Rules of Air Warfare/Chapter IV: Hostilities/Bombardment; Article 24, available at: https://ihl-databases.icrc.org/applic/ihl/ihl.nsf/ART/275-370036?OpenDocument&xp_articleSelected=370036 .

58 Since the Crimean War, in the middle of the nineteenth century, the print media had played a key role in covering even faraway conflicts by enabling people to experience them from day to day, as they developed. Bacot, Jean-Pierre, “Le rôle des magazines illustrés dans la construction du nationalisme au XIXe siècle et au début du XXe siècle”, Réseaux, No. 107, 2001, pp. 265–293 CrossRefGoogle Scholar.

59 Article 29 of the Hague Convention II states that “soldiers not in disguise who have penetrated into the zone of operations of a hostile army to obtain information are not considered spies”, above note 21.

60 Admiral Sir Bacon, R. H. (ed.), The Life of Lord Fisher of Kilverstone, Vol. 2, London, 1929, p. 144Google Scholar, quoted in Heidi J. S. Tworek, “Wireless Telegraphy”, 8 March 2016, available at: http://encyclopedia.1914-1918-online.net/article/wireless_telegraphy.

61 Lehmann, Ernst, Auf Luftpatrouille und Weltfahrt, Volksverband der Bücherfreunde (Air Patrols and World Travel: Book-Lovers’ Unit), Berlin, 1936, pp. 60 and 67Google Scholar.

62 The “spy basket” of the Zeppelin LZ90, found near Colchester in September 1916, is displayed in the Imperial War Museum in London.

63 Like Lieutenant Conrad von Belke, a character in Joseph Storer Clouston's novel The Spy in Black (William Blackwood, Edinburgh, 1917, made into a film by Michael Powell in 1939).

64 Text printed on the back “With the British Navy in wartime. A submarine submerging” with stamps “Official Photograph issued by the Press Bureau” and “Passed for transmission abroad”.

65 Antier, Chantal, “Espionnage et espionnes de la Grande Guerre” (Spying and Female Spies in the Great War), Revue historique des armées, No. 247, 2007, pp. 42–51 Google Scholar, available at http://rha.revues.org/1963 .

66 Bertrand Warusfel, “Histoire de l'organisation du contre-espionnage français 1871–1945”, Cahiers du Centre d’Études d’Histoire de la Défense, Vol. 1, CEHD, Paris, 1996, p. 13, available at: http://www.droit.univ-paris5.fr/warusfel/articles/HistoireCE_warusfel96.pdf; Paul Émil von Lettow-Vorbeck et al., L’espionnage et le contre-espionnage pendant la guerre mondiale d’après les archives militaires du Reich, Nouveau Monde éditions, Paris, 2012.

67 As affirmed by the Belgian spy Marthe McKeena, Comment on devient espion, Payot, 1935, quoted by C. Antier, above note 65. Victor Saville, I Was a Spy!, 1933.

68 William Somerset Maugham recounts this episode in the 1941 preface to his short-story collection Ashenden, or The British Agent (first published in 1927).

69 After the most recent conflicts the United States has been involved in, there have been more veterans’ suicides than there were deaths on the battlefield. Herbert Hendin, “Healing The Hidden Wounds of War: Treating The Combat Veteran With PTSD at Risk For Suicide”, Huffington Post, 18 September 2013, available at: http://www.huffingtonpost.com/herbert-hendin/healing-the-hidden-wounds_b_3948156.html.

70 Chapter II of the Hague Convention (II) is devoted to spies, and defines the category by specifying its legal status in a conflict. The text is careful to stipulate that “individuals sent in balloons” must be considered combatants, not spies (Article 29).

71 On this kind of legislation, adopted in the last third of the nineteenth century, see Sébastien Laurent, Politiques de l’ombre. État, renseignement et surveillance en France (Politics of the Shadows. The State, Intelligence and Surveillance in France), Fayard, Paris, 2009.

72 According to a report by a working group headed by Antoine Prost, Quelle mémoire pour les fusillés de 1914–1918? Un point de vue historien, Report submitted to the Minister Delegate for Veterans’ Affairs, 1 October 2013, p. 12, available at: http://www.ladocumentationfrancaise.fr/var/storage/rapports-publics/134000666/0000.pdf.

73 In France, this was reflected in the 1912 vote making it compulsory for Nomadic people to carry an anthropometric identity booklet, and the 1917 decree introducing a compulsory identity card for foreigners. Even after the war had ended, an order dated 14 December 1918 introduced a special identity card for people from Alsace and the Moselle, who were divided into four classes, A to D, depending on their degree of “Germanic” or “French” ancestry.

74 This was the slogan officially adopted by the ministerial circular of 28 October 1915; http://verdun-meuse.fr/index.php?qs=fr/ressources/objet-du-mois---novembre-2010---assiette-tais.

75 Daniel G. Donaldson, The Espionage and Sedition Acts of World War I: Using Wartime Loyalty Laws for Revenge and Profit, LFB Scholarly Publications, El Paso, TX, 2012.

76 In the immediate post-war period, this progress (described in the article by G. Marin, above note 3, pp. 516–518) caused radio to take off as a means of communication.

77 “CIA reveals invisible ink recipes used by WWI spies”, BBC News, 20 April 2011, available at: http://www.bbc.co.uk/news/world-us-canada-13141473. At her trial, Mata Hari admitted that she had thrown the compromising inkbottle into the sea.

78 Some of these sectioned cables would be used to make new connections, such as the cables linking Brest with Casablanca in 1915 and Casablanca with Dakar in 1916. Fouchard, Gérard, “Le câblage de l'Afrique de l'Ouest”, Bulletin de l’Association des amis des câbles sous-marins, No. 47, June 2013, p. 16Google Scholar, available at: http://www.cablesm.fr/bulletin47.pdf.

79 Association des amis des câbles sous-marins (Friends of Underwater Cables), “Le réseau gouvernemental et les compagnies télégraphiques allemandes”, available at: http://www.cablesm.fr/Les%20compagnies%20allemandes%20_2_.pdf.

80 The telegram sent on 16 January 1917 by the German Minister for Foreign Affairs, Arthur Zimmermann, to the Mexican government proposed that Mexico should enter the war against the United States in exchange for financial support and the promise that it could annex three American states (Texas, Arizona and New Mexico).

81 Gary Warne, “The Predator's Ancestors – UAVs in The Great War”, 25 July 2012; available at: http://warnepieces.blogspot.ca/2012/07/the-predators-ancestors-uavs-in-great.html.

82 Ernest Swinton used this expression to refer to the “wilderness of dead bodies… between the opposing lines” in his short story “The Point of View”, published under the pseudonym of Ole Luk-Oie. The Green Curve and Other Stories, Doubleday, Page & Company, Garden City, NY, 1914, p. 243.

83 According to John Weldon the word “tank” was used instead of “machine gun destroyer”. Weldon, John, “A short history of tank development: Seven tanks for armoured warfare”, Meccano Magazine, July 1970, pp. 370–373 Google Scholar.

84 Ernest Swinton, The Green Curve and Other Stories, above note 82, 1918, p. 4. We are not told whether these rumours were created deliberately or whether they were just left to occur naturally, in accordance with a phenomenon ably examined by Marc Bloch (quoted below).

85 “… it was naturally realised that the greatest results to be expected from the employment of this new weapon would be attained if it could be launched unexpectedly, so that the enemy might be caught unprepared to meet it.” Ernest Swinton, The “Tanks” (by request and with permission), George H. Doran Company, NY, March 1918, p. 3, available at: https://archive.org/stream/tanksbyrequestwi00swin_0/tanksbyrequestwi00swin_0_djvu.txt.

86 Text printed on the back side of the photograph: “Official Photographs taken on the British Western Front. The Battle of the Menin Road [20–25 September 1917]” and interestingly the text continues: “One of our latest tanks going to destroy German machine gun positions” [the machine gun being considered as a more “inhumane” type of modern weaponry]; with stamps “Official Photograph issued by the Press Bureau” and “Passed for transmission abroad”.

87 In fact, it was a German monoplane that carried out the first “psychological warfare” operation by flying over Paris on Sunday, 30 August 1914 with a banner in the colours of the Reich. It dropped pamphlets bearing the message: “The German army is at the gates of Paris, it only remains for you to surrender.” Jean Hallade, 1914–1918: De l’Aisne on bombardait Paris, Imprimerie de l'Aisne Nouvelle, 1979; quoted in “L'aviation allemande bombarde Paris, en août et septembre 1914”, 1914 – Première bataille de la Marne – First Battle of the Marne, available at: http://1914ancien.free.fr/parisbom.htm.

88 Swinton, Ernest, Eyewitness: Being Personal Reminiscences of Certain Phases of the Great War, Including the Genesis of the Tank, Doran & Company, Garden City, NY, 1933, pp. 47–50 Google Scholar.

89 In June 1917 the German Minister for Foreign Affairs told his Swiss counterpart that any aviator dropping propaganda would be regarded as breaking the laws of war – a threat carried out in December of the same year. Wilkin, Bernard, “Propagande militaire aérienne et législation durant la Première Guerre mondiale”, Revue historique des armées, No. 274, 2014, pp. 87–94 Google Scholar, available at: http://rha.revues.org/7976.

90 Available at: http://upload.wikimedia.org/wikipedia/commons/e/ec/It_is_far_better_to_face_the_bullets.jpg. See also the poster “Zeppelins Over Your Town”, available at: http://www.iwm.org.uk/collections/item/object/30918. For the print media, see the photo of an airship under the beams of projectors, which appeared on the front page of the 8 November 1915 issue of the American illustrated weekly The Independent and of L’Illustration, No. 3760, 27 March 2015 (see Figure 3).

91 W. A. Gullick, “Enlist, by staying at home you are giving your approval to this kind of thing”, picture, in Collection of New South Wales recruitment posters for World War I, available at: http://nla.gov.au/nla.pic-an7697018-3.

92 An analogy with an entertaining hunting activity currently featuring in anti-armed drones campaigns which condemn the “PlayStation mentality” of pilots accused of having a virtual – and obscenely game-inspired – image of their targets.

93 This despite the fact that there was nothing spontaneous about the pictures, which had been carefully staged. Sur le vif and J’ai vu were two magazines, founded during the war, in which illustrations were more important than commentary. Guillot, Hélène, “La section photographique de l'armée et la Grande Guerre”, Revue historique des armées, No. 258, 2010, pp. 110–117 Google Scholar, available at: http://rha.revues.org/6938.

94 The SPA and SCA were merged in January 1917. Challeat, Violaine, “Le cinéma au service de la défense, 1915–2008”, Revue historique des armées, No. 252, 2008, pp. 3–15 Google Scholar, available at: http://rha.revues.org/2983.

95 Such as the screenwriter and director Henri Desfontaines, ibid., note 7. Across the Atlantic, Charlie Chaplin was making several propaganda films: Zepped, The Bond and the comedy Shoulder Arms. “World One War: Charlie Chaplin”, HubPages, 29 April 2011, available at: http://smnmcshannon.hubpages.com/hub/World-One-War-Charlie-Chaplin.

96 The Bureau de la Presse in Paris in January, the Oberzensurstelle in Berlin in February and the Official Press Bureau in London in June 1915; Eberhard Demm, “Censorship”, 8 March 2016, notes 4 and 9, available at: http://encyclopedia.1914-1918-online.net/article/censorship.

97 Ibid ., note 11.

98 Marc Bloch, “Réflexions d'un historien sur les fausses nouvelles de la guerre” (A historian's reflections on false news during the war), Revue de synthèse historique, Vol. 33, August–December 1921, p. 32.

99 This feeling of irrationality and false reality found radical artistic expression, for example in the Dada movement, which emerged in those years and spread throughout the world.

100 Ibid ., p. 19.

101 Ibid ., pp. 32–33.

102 On the role played by this news agency in connection with German consuls, businessman volunteers and associations of Germans resident overseas, see Jamie Bisher, The Intelligence War in Latin America, 1914–1922, McFarland, Jefferson (NC), 2016, p. 32.

103 http://www.sayville.com/wireless.html.

104 After declaring war on Germany on 6 April 1917, one of the first hostile acts of the United States was to seize the Sayville Station. However, this had little effect on the German world broadcasting capacity, as by that time the long-wave radio station at Nauen could transmit messages over 11,000 kilometres. H. Tworek, 2016,  above note 60.

105 Schwanitz, Wolfgang G., “Euro-Islam by ‘Jihad made in Germany’”, in Clayer, Nathalie and Germain, Éric (eds), Islam in Inter-War Europe, Hurst, London, 2008, pp. 271–301 Google Scholar.

106 The British effort at mobilizing religious affects seems to have been more amateurish. In 1933 Colonel Swinton admitted that his idea of painting hideous genies on the armour of tanks sent to fight in Palestine – in the hope of giving the enemy an even greater fright – had been inspired more by his familiarity with the Arabian Nights than by any real knowledge of the region's culture. E. Swinton, Eyewitness, above note 88, 1933, pp. 260–261. To encourage the Bedouin tribes to revolt, T. E. Lawrence had inflamed not their religious affects but nationalist Arab feeling.

107 “L'avion sans pilote” (The Pilotless Plane), in Journal des Voyages, 4 April 1929, reprinted in Le Piège, No. 208, March 2012, available at: http://www.aea.asso.fr/public/lepiege/sommaires/2012.html.

108 J. H. Morrow, above note 44, p. 411.

109 This little silent film, inspired by H. G. Wells and Jules Verne and directed by Walter Booth, imagined the city of London attacked by a fleet of aircraft but saved by the invention of a radio-guided aerial torpedo. IMDb entry available at: http://www.imdb.com/title/tt0000790/?ref_=ttrel_rel_tt.

110 Jonathan Sale, “The secret history of drones”, in The Guardian, 10 February 2013, available at: http://www.theguardian.com/world/shortcuts/2013/feb/10/secret-history-of-drones-1916.

111 “Deadly Air Torpedo Ready at War's End: Elmer Sperry's Invention Is Told”, in the New York Times, 8 December 1926, quoted in Hughes, Thomas P., American Genesis: A Century of Invention and Technological Enthusiasm, 1870–1970, University of Chicago Press, Chicago, 2004, p. 128Google Scholar.

112 In Germany, the Krupp factories had been working on the concept of an aerial torpedo from 1909, drawing on the work of a Professor Weichert: “Torpedoes That Fly In The Air: Krupp's Subvention of a New Aerial Monster”,  New Zealand Herald, Vol. 46, No. 14079, 5 June 1909, p. 2Google Scholar, available at: http://paperspast.natlib.govt.nz/cgi-bin/paperspast?a=d&d=NZH19090605.2.98.32.

113 Agence Rol, “Torpille radio automatique Gabet”, picture, Rol 7510, 24 December 1909, available at: http://gallica.bnf.fr/ark:/12148/btv1b6913022n; Agence Rol, “Torpille dirigible Gabet”, picture, Rol 5070, 31 August 1909, available at: http://gallica.bnf.fr/ark:/12148/btv1b6912353x. See also “Invention d'une torpille radio automatique”, Le Petit Journal, 14 February 1909.

114 Reminiscent of the words of Orville Wright: “When my brother and I built and flew the first man-carrying flying machine, we thought that we were introducing into the world an invention which would make further wars practically impossible.” Orville Wright to C. M. Hitchcock, letter, 21 June 1917, available at: http://www.smithsonianeducation.org/educators/lesson_plans/wright/flights_future.html.

115 Paul Aubriot, “Chars d'assaut – premiers efforts” (Tanks – first attempts), in Le Midi, 7 September 1918, available at: http://images.midi.bibliotheque.toulouse.fr/1918/B315556101_MIDSOC_1918_09_07.pdf.

116 This pioneering research is described in Peter Singer's best-seller, Wired for War: The Robotics Revolution and Conflict in the 21st Century, Penguin Press, New York, 2009 Google Scholar; and in Robert Work and Shawn Brimley (eds), 20YY: Preparing for War in the Robotic Age, report, Center for a New American Security (CNAS), Washington, DC, 22 January 2014, p. 22, available at: http://www.cnas.org/20YY-Preparing-War-in-Robotic-Age#.UzU9ldhAfEY.

117 “1919 – Quelques chars, guerre et après-guerre” (1919 – Some tanks, war and post-war), Vieux-Papiers, 14 February 2010, available at: http://vieux-papiers.over-blog.com/article-1919-quelques-chars-guerre-et-apres-guerre-44917424.html; “Torpille Terrestre” (Ground Torpedo), Le Bestiaire Extraordinaire de l’Armée Française, 2005, available at: http://modelarchives.free.fr/Bestiaire/Torpter_P/; “1915 Cuirasse Aubriot-Gabet”, Un siècle d’histoire des engins blindés français (French Armoured Vehicles: A Century of History), available at: http://www.chars-francais.net/new/index.php?option=com_content&task=view&id=787&Itemid=36.

118 This section draws on some ideas originally presented in the article by É. Germain, “L'ennemi…Toujours plus loin”, above note 9, p. 31–32.

119 Colonel Armengaud, “L'aviation militaire au Maroc au cours du 2e trimestre 1925. Les opérations”, Revue de l’aéronautique militaire, September–October 1925, p. 101, quoted by Millet, Jerôme, “L'aviation militaire française dans la guerre du Rif” (The French air force in the Rif War), Revue historique des armées, No. 166, March 1987, p. 49Google Scholar.

120 The efficacy of the British “air control” doctrine was somewhat downplayed on the French side. According to the commander of the colonial air force in Morocco, the experience of the Rif War showed that “it is not enough, as some have feigned to believe, to reach the Rifian in his home with aerial bombings: we must conquer his country's sensitive points by bringing a column of all kinds of weapons there…”. Colonel Armengaud's report of 19 July 1925 for his superior, Marshal Lyautey, quoted by J. Millet, ibid., p. 52.

121 An asymmetry that was already precarious, as illustrated by a 1925 intelligence memorandum warning that Abd el-Krim might resort to mercenary pilots for flying his three planes in Morocco. Ibid., p. 57.

122 Winston Churchill, “…one can clearly see that the conquest of the air may mean the subjugation of mankind and the destruction of our civilization”, House of Commons, 7 June 1935, quoted by Richard M. Langworth (ed.), “Churchill and the ‘Flying Peril,’ 1913–1955”, available at: http://www.winstonchurchill.org/images/pdfs/for_educators/The%20Flying%20Peril.pdf".

123 Royal Air Force, “Remotely Piloted Air System (RPAS): 39 Squadron”, available at: http://www.raf.mod.uk/organisation/39squadron.cfm.

124 Chris Woods, “CIA's Pakistan drone strikes carried out by regular US air force personnel”, in The Guardian, 14 April 2014, available at: http://www.theguardian.com/world/2014/apr/14/cia-drones-pakistan-us-air-force-documentary".

125 A very particular kind of war, with no declaration of war and even no army, with terrorists on one side and a civilian intelligence agency on the other. Moreover, this fleet of armed drones is said to be piloted mostly by operators from private companies, under contract. See Peter W. Singer, “Double-Hatting Around the Law: The Problem with Morphing Warrior, Spy and Civilian Roles”, in Armed Forces Journal, Brookings Institution, Washington, DC, 1 June 2010, available at: http://www.brookings.edu/research/opinions/2010/06/01-military-roles-singer.

126 With the accuracy of the air-dropped guided munitions touted in the CNAS report 20YY: Preparing for War in the Robotic Age, above note 116, pp. 10–16.

127 There is even talk about hackers being affected by this type of post-traumatic stress disorder. The group of internet activists going by the name of Telecomix – whose We Rebuild campaign has enabled activists from the revolutions in Tunisia, Egypt and Syria to bypass censorship since 2011 – have set up a help unit for members who have been psychologically damaged by viewing unbearable images.

128 “L’œuvre d'un grand français” (The Work of a Great Frenchman), Le Gaulois, 7 August 1911, available at: http://gallica.bnf.fr/ark:/12148/bpt6k5351462.texte.

129 Philip J. Haythornthwaite, The World War One Source Book, Arms & Armour Press, London, 1993. Each camp lost more than nine million lives, both military and civilian.

130 Bernhard Schwertfeger, Kaiser und Kabinettschef: nach eigenen Aufzeichnungen und dem Briefwechsel des […] Rudolf von Valentini (The Kaiser and the Head of Cabinet: from Rudolf von Valentini's own records and correspondence), Gerhard Stalling, Oldenburg, 1931, p. 144, quoted in Bayerische Landeszentrale für Politische Bildungsarbeit, “Keine Chance auf Frieden? Außenpolitik 1917” (No Chance for Peace? Foreign Policy 1917), March 2007, available at: http://www.blz.bayern.de/blz/eup/03_07_themenheft/3.asp.

131 On the issues raised by “autonomous lethal robots”, which I include in the wider category of “coercion robotics”, see Éric Germain, “La campagne pour l'interdiction des ‘robots tueurs’ se trompe-t-elle de cible?” (Is the campaign to ban ‘killer robots’ mistaking its target?), in Le Monde, 24 June 2013, available at: http://www.lemonde.fr/idees/article/2013/06/24/la-campagne-pour-l-interdiction-des-robots-tueurs-se-trompe-t-elle-de-cible_3435578_3232.html.

132 A high-level meeting of experts, chaired by the French ambassador, was held at the Palais des Nations (UN) in Geneva from 13 to 16 May 2014 under the 1980 Convention on Conventional Weapons (CCW); the agendas for the three meetings organized since then, and their final reports, are available at: http://www.unog.ch/80256EE600585943/(http://Pages)/8FA3C2562A60FF81C1257CE600393DF6?OpenDocument.