The occupation of İstanbul and İzmir by the Allies in the aftermath of World War I prompted the establishment of the Turkish national movement.Under the leadership of Mustafa Kemal Pasha, a military commander who had distinguished himself during the Battle of Gallipoli, the Turkish War of Independence was waged with the aim of revoking the terms of the Treaty of Sèvres.By September 18, 1922, the occupying armies were repelled and the country saw the birth of the new Turkish state. On November 1, the newly founded parliament formally abolished the Sultanate, thus ending 623 years of Ottoman rule. The Treaty of Lausanne of 1923 led to the international recognition of the sovereignty of the newly formed "Republic of Turkey" as the successor state of the Ottoman Empire, and the republic was officially proclaimed on October 29, 1923, in the new capital of Ankara.Mustafa Kemal became the republic's first president and subsequently introduced many radical reforms with the aim of founding a new secular republic from the remnants of its Ottoman past.[5] According to the Law on Family Names, the Turkish parliament presented Mustafa Kemal with the honorific name "Atatürk" (Father of the Turks) in 1934.Turkey entered World War II on the side of the Allies on February 23, 1945 as a ceremonial gesture and became a charter member of the United Nations in 1945.Difficulties faced by Greece after the war in quelling a communist rebellion, along with demands by the Soviet Union for military bases in the Turkish Straits, prompted the United States to declare the Truman Doctrine in 1947. The doctrine enunciated American intentions to guarantee the security of Turkey and Greece, and resulted in large-scale US military and economic support.After participating with the United Nations forces in the Korean conflict, Turkey joined the North Atlantic Treaty Organization (NATO) in 1952, becoming a bulwark against Soviet expansion into the Mediterranean. Following a decade of intercommunal violence on the island of Cyprus and the subsequent Athens-inspired coup, Turkey intervened militarily in 1974. Nine years later Turkish Republic of Northern Cyprus (TRNC) was established. TRNC is recognised only by Turkey.Following the end of the single-party period in 1945, the multi-party period witnessed tensions over the following decades, and the period between the 1960s and the 1980s was particularly marked by periods of political instability that resulted in a number of military coups d'états in 1960, 1971, 1980 and a post-modern coup d'état in 1997.The liberalization of the Turkish economy that started in the 1980s changed the landscape of the country, with successive periods of high growth and crises punctuating the following decades.