The Nyon Conference was a diplomatic conference held in Nyon, Switzerland, in September 1937 to address attacks on international shipping in the Mediterranean Sea during the Spanish Civil War. The conference was convened in part because Italy had been carrying out unrestricted submarine warfare, although the final conference agreement did not accuse Italy directly; instead, the attacks were referred to as "piracy" by an unidentified body. Italy was not officially at war, nor did any submarine identify itself. The conference was designed to strengthen non-intervention in the Spanish Civil War. The United Kingdom and France led the conference, which was also attended by Bulgaria, Egypt, Greece, Romania, Turkey, the Soviet Union and Yugoslavia.
The first agreement, signed on 14 September 1937, included plans to counterattack aggressive submarines. Naval patrols were established; the United Kingdom and France were to patrol most of the western Mediterranean and parts of the east, and the other signatories were to patrol their own waters. Italy was to be allowed to join the agreement and patrol the Tyrrhenian Sea if it wished. A second agreement followed three days later, applying similar provisions to surface ships. Italy and Germany did not attend, although the former took up naval patrols in November. In marked contrast to the actions of the Non-Intervention Committee and the League of Nations, this conference succeeded in preventing attacks by submarines.
Nyon has been characterised as "an appeasers paradise. The fiction that attacks on merchant shipping in the Mediterranean was the fault of 'pirates unknown' was fully indulged. [It] preserved the naval status quo in the Mediterranean until the end of the Spanish Civil War: the Francoists received whatever they wanted, the Republicans got very little." Michael Alpert, "Contrasting Ways of War in Spain, 1936–39", War in History, 6/3 (1999), pp. 331–51; Dominic Tierney, "Franklin D. Roosevelt and Covert Aid to the Loyalists in the Spanish Civil War, 1936–39", Journal of Contemporary History, 39 (2004), pp. 299–313; The Bitter Sea, by Simon Ball, p. 14.
Context and organisation The Non-Intervention Committee, a group of twenty-four nations set up in 1936 and based in London, had attempted to restrict the flow of weapons to the parties of the Spanish Civil War.Gretton (1975). p. 103. For the United Kingdom, it formed part of the policy of appeasement towards Germany and Italy and aimed at preventing a proxy war – with Italy and Germany supporting Franco's Nationalist Coalition on one side and the Soviet Union supporting the Republican faction on the other – from escalating into a major pan-European conflict.Stone (1997). p. 134.Frank (1987). pp. 390–391. An Anglo-Italian "Gentleman's Agreement" had been signed on 2 January 1937, with each party respecting the rights of the other in the Mediterranean and aimed at improving Anglo-Italian relations. In May 1937, Neville Chamberlain succeeded Stanley Baldwin as British Prime Minister, and adopted a new policy of dealing directly with Germany and Italy.Mills (1993). p. 1. The British believed they could convince Italy to abandon Germany through appeasement.Thomas (1961). pp. 475–476.
Under a Non-Intervention Committee plan, neutral observers were posted to Spanish ports and borders.Thomas (1961). p. 394. The plan also assigned zones of patrol to the United Kingdom, France, Germany and Italy, and patrols began in April.Thomas (1961). p. 395. Following attacks on the German cruiser Leipzig on 15 and 18 June, Germany and Italy withdrew from the patrols.Thomas (1961). p. 457.Bulletin of International News (August 1937). pp. 4–5. The United Kingdom and France offered to replace Germany and Italy in patrols of their sections, but the latter powers believed these patrols would be too partial.Bulletin of International News (August 1937). p. 7. The British Admiralty proposed four plans in response to attacks on British shipping, favouring sending significant naval resources to the Mediterranean as the best solution;Gretton (1975). p. 105. previous control measures had been widely evaded. As suspected by the other powers, Italy was behind some of these attacks.Gretton (1975). p. 104. Whilst officially being at peace, the Italian leadership had ordered the commencement of unrestricted submarine warfare, referred to in discussion as a campaign of piracy without mention of Italy. These plans would be the basis for a Mediterranean meeting, suggested by French Foreign Minister Yvon Delbos. Meanwhile, on the night of 31 August to 1 September, the Italian submarine Iride unsuccessfully attacked the British destroyer Havock with torpedoes, between the Gulf of Valencia and the Balearic Islands, strengthening British Foreign Secretary Anthony Eden's sceptical stance towards Italy.Mills (1993). p. 12. The attack led the British representative in Rome to protest to the Italian Minister of Foreign Affairs, but without response.
Up to 60,000 Italian volunteers were then operating in Spain,Alpert (1998). p. 115. and the removal of foreign nationals was discussed by the Non-Intervention Committee.Bulletin of International News (August 1937). pp. 11–12. Italy had made a declaration on 7 January 1937 that it would stop Italian volunteers from fighting in Spain.Thomas (1961). p. 340. and put a moratorium on volunteers on 20 January, also agreeing to support limitations on the number of volunteers on the 25th.Alpert (1998). p. 104. Italy continued to request that belligerent rights be given to the Nationalists and Republicans, so both would gain the right to search vessels for contraband, thus removing the need for naval patrols.Thomas (1961). p. 457. This request was opposed by the United Kingdom, France and the Soviet Union.Bulletin of International News (August 1937). pp. 7–8. British recognition of Italian sovereignty over Abyssinia following the Second Italo-Abyssinian War was an important issue during Anglo-Italian discussions in August 1937. Following Eden's disagreement with Chamberlain and Lord Halifax, Leader of the House of Lords and influential politician, over the issue, any agreement recognising Italian sovereignty was postponed until after the planned shipping conference had taken place.Mills (1993). pp. 10–13.
On 5 or 6 September, the British arranged a conference for all parties with a Mediterranean coastline, along with Germany.Gretton (1975). p. 106.Thomas (1961). p. 475. The conference was to be held at Nyon, Switzerland – Geneva was avoided because Italians associated it with the actions of the League of Nations over the Abyssinian Crisis. The United Kingdom agreed to France's request to extend an invitation to the Soviet Union, but blocked France's attempt to invite a representative from Republican Spain. Portugal expressed surprise at not being invited. Camille Chautemps, the new French Prime Minister, opposed direct intervention on the Spanish question.Mills (1993). p. 13. The Soviet Union accepted the invitation, indicating that it would use the opportunity to blame Italy for the attacks on shipping. The Soviet government formally accused the Italians of sinking two Soviet merchant vessels, the Timiryazev and the Blagoev,Thomas (1961). p. 476. an accusation the Italians described as "aggressive and offensive". This was perhaps an attempt by the Soviet Union to push Italy and Germany away from the conference. Germany rejected the invitation, stating that piracy and other issues the conference was to discuss should be handled only by normal meetings of the Non-Intervention Committee, not a conference like Nyon. The United Kingdom and France rejected this suggestion, and continued to prepare for the conference. Soon after, the Italians similarly declined. The Non-Intervention Committee, it said, also had the advantage of including other European powers, notably Poland and Portugal.
Provisions British and French naval staffs rejected the idea of a convoy system in draft proposals. The British wanted to curb submarine activity, on the theory that focusing on covert submarine attacks would help avoid confrontation, whereas the French considered surface vessels and aircraft just as important. The French protested at a plan to create multi-nation squadrons, unhappy at the prospect of French ships coming under foreign command. On 8 September, plans were discussed in the British Cabinet, including the setting up of eight groups of three destroyers for the western Mediterranean. Preliminary talks with the French were held on 9 September,Gretton (1975). p. 107. and the conference began on the 10th. Proceedings took two forms: discussions between the British and French, and formal meetings of all attending parties. Many of the other nations opposed the participation of the Soviet Navy in the Mediterranean, so the United Kingdom and France agreed to handle Aegean Sea patrols. This was, perhaps surprisingly, accepted by the Soviet Union.Gretton (1975). p. 108.
The conference ended on 14 September with the signing of the "Mediterranean Agreement". Signatories were the countries of Bulgaria, Egypt, France, Greece, Romania, Turkey, the United Kingdom, the USSR and Yugoslavia. The agreement noted attacks on neutral shipping by submarines, in contravention of the London Naval Treaty (signed in 1930) and the Submarine Protocol, part of the Second London Naval Treaty (signed in 1936).Bulletin of International News (September 1937). p. 12.
The agreement provided that any submarine that attacked neutral shipping was to be sunk if possible, including submarines in the vicinity of a recent attack that were determined to be responsible for the attack. French and British fleets would patrol the seas west of Malta and attack any suspicious submarines, with the division of patrols between the United Kingdom and France to be decided by their governments. Both countries would patrol the high seas and territorial waters of signatory countries in the Mediterranean. The British would provide slightly more than half the 60 destroyers needed, with the French providing the remainder and most of the accompanying aircraft. It was agreed that Italy could participate in patrols of the Tyrrhenian Sea if it wished to do so. In the Eastern Mediterranean, British and French ships would patrol up to the Dardanelles, but not in the Adriatic Sea. In this area, signatory countries would patrol their own territorial waters, and would provide any reasonable assistance to the French and British patrols. The future revision of these provisions, including the way the area had been divided into zones, was specifically allowed. Submarine activity would be banned, subject to two exemptions: travel on the surface accompanied by a surface ship, and activity in certain areas for training purposes. Governments would only allow foreign submarines into each of their territorial waters in extreme situations, such as immediate distress. Merchant shipping would also be advised to stick to particular shipping routes. The agreement repeated the suggestion that Italy join in the proposal.Bulletin of International News (September 1937). p. 13. Delbos announced that similar proposals about surface craft would be prepared. The provisions of the agreement would come into force on 20 September. The British and French knew that the secret Italian submarine operations had already been paused, but actions to enforce the conference agreement started at midnight on 19/20 September. The delegates to the agreement were happy; The Times likened them to cricketers, "reviewing their innings, over by over".