The Salonika Agreement (also called the Thessaloniki Accord) was a treaty signed on 31 July 1938 between Bulgaria on the one hand and the Balkan Entente—the states of Greece, Romania, Turkey and Yugoslavia—on the other. The signatories were, for the former, Prime Minister Georgi Kyoseivanov and, for the latter, in his capacity as President of the Council of the Balkan Entente, Ioannis Metaxas, Prime Minister and Foreign Minister of Greece.
The agreement was the result of the realization by the Entente that Bulgaria alone could not threaten the members of the Entente acting in concert, and that the Bulgarian government desired to follow a policy of peace. There were at least two signs of this. A protocol signed at Belgrade on 17 March 1934 by the Balkan Entente was published privately in May, revealing that the members had plans to jointly occupy Bulgaria if efforts to suppress terrorist organizations operating out of her territory were not successful. The new Bulgarian government of Kimon Georgiev, coming to power on 19 May, responded to the private revelation by clamping down on the Internal Macedonian Revolutionary Organization. Then, on 24 January 1937, Bulgaria concluded a treaty of eternal friendship with Yugoslavia, which was approved by the other members of the Entente. (Initially Greece was very hostile.) In November 1936, the chiefs of staff of the four Balkan powers signed a draft military alliance, which was subsequently confirmed as an integral part of the Balkan Pact at the meeting of the Balkan Council on 15–18 February 1937.
The agreement removed the arms restrictions placed on Bulgaria after World War I by the Treaty of Neuilly-sur-Seine, and allowed her to occupy the demilitarised zone bordering Greece. The demilitarised zones along the Turkish borders with Bulgaria and Greece, a result of the Treaty of Lausanne, were also abandoned. All the parties committed to a policy of non-aggression, but Bulgaria was not forced to abandon her territorial revisionism.
Bulgarian re-armament
Bulgaria had long protested the restrictions placed on armaments at Neuilly, but she, unlike Austria, Germany and Hungary, had a good track record of abiding by them. In the 1930s she began to evade them, buying military equipment from Germany, but being refused orders placed in Britain. The Bulgarians argued, and in this they had the support of the United States, that the League of Nations, which was designed to protect weak and disarmed states, was not powerful enough to protect Bulgaria. In November 1937, when the pace of re-armament had picked up, a British memorandum advised a "blind eye" policy towards it, and placing pressure on the Entente and France to do the same, in order to prevent Bulgaria from falling under the influence of the Italo-German axis. The British memo specified that Bulgaria was set to violate all the pertinent articles of the treaty:
The relevant articles of the treaty are #78, which prohibits fortification of any further places in Bulgaria, #81, which prohibits the importation of arms, munitions, and war materials of all kinds, #82, prohibiting the manufacture and importation into Bulgaria of armoured cars, tanks and any similar machines suitable for use in war, #86, which prohibits the construction or acquisition of any submarine, even for commercial purposes and #89, which prohibits the inclusion in the armed forces of Bulgaria of any military or naval air forces.
Although initially Turkey was strongly opposed to Bulgaria's accelerated re-armament in 1934—especially on account of the weakness of the Greek army—by the time of the Salonika agreement, it was accepted as a fait accompli.