Öz In August 1937 indiscriminate attacks upon merchant ships in the Mediterranean by unidentified submarines had begun. Most alarming for Turkey, some of these submarines were operating inside the Straits. On 10-14 September 1937 an international conference, on the initiative of Britain and France, was organised at Nyon for ending the existing state of insecurity in the Mediterranean. On 14 September, it was agreed that pirate submarines should be counter-attacked and destroyed. Turkey promised to provide bases for the patrolling vessels. Turks were also responsible for patrols in the Dardanelles. The outcome of the conference was welcomed by Atatürk, whereas İnönü's reaction was mixed. i.e. one of criticism and praise. Turkey, on Atatürk's instructions, co-operated fully in the international patrol set up by the conference to suppress pirate submarines. But İnönü showed caution over the agreement, apprehending about a war with Italy. The measures agreed upon at Nyon proved effective. Submarine piracy quickly disappeared. By its signature of the Nyon Agreement, Turkey stressed its interest in preserving the status quo and the principle of collective security. It was therefore drawn towards closer co-operation with Britain and France. The trend towards rapprochement was reciprocal, since these two countries also needed Turkey's co-operation.