 This video will outline the development of NATO during the Cold War, highlighting the main issues, events and decisions that shaped the history of the Alliance. While the territorial scope of the Alliance, defined by Article 6 of the North Atlantic Treaty, did not include Asia. Ironically, soon after the signing of the North Atlantic Treaty, developments taking place in the Asian continent would have a profound impact on the evolution of the Alliance. The analogy between a divided Korea and the Division of Germany obviously resounded deeply within Alliance members, particularly as war broke out in the Korean Peninsula in June 1950. The perception in the West was not only one of communist aggression, but of the unity of purpose of two communist giants, given the creation of the People's Republic of China in October 1949. The red scare impacted severely on threat assessments in Washington. As the iconic and emblematic document of the U.S. National Security Council, NSC-68 stated, the Cold War is in fact a real war in which the survival of the free world is at stake. In the United States, this resulted in increased defense spending and a substantial reorientation of national security concerns to focus on the need to be prepared for potential war in Europe. Consequently, the North Atlantic Treaty assumed an even greater importance for Washington. Following the outbreak of the Korean War, in fact, the Allies decided to strengthen the integrated military structure of the Alliance. By the end of 1950, the Alliance had a Supreme Allied Commander, General Dwight Eisenhower, and operational headquarters near Paris, the Supreme Headquarters Allied Powers Europe, or SHAPE. A few years later, as the Korean War continued to wage, the North Atlantic Council meeting in Lisbon formally recognized the structure of the Alliance. The North Atlantic Treaty had thus evolved into NATO, a permanent military organization. Concurrently, the Alliance also moved to strengthen its southern flank, signalling the growing strategic importance of the Mediterranean. In February 1952, recent Turkey entered NATO, thereby greatly strengthening the Alliance's southern flank. The militarization of the Cold War therefore had a direct impact on the evolution of NATO. As greater emphasis was given to military preparedness and to deterring a potential communist aggression in Western Europe, throughout the 1950s, the issue of the rearmament of Germany became the dominant question. While the European countries had tried to respond to the shift in threat perception with the proposal on a European defence community, the so-called Pleuven Plan, domestic opposition in France prevented the plan from evolving further. Consequently, the idea of including a re-armed Federal Republic of Germany in the Atlantic Alliance started to take hold. In October 1954, the three Western powers terminated their occupation regimes and recognized the Federal Republic of Germany as a sovereign state. This paved the way for the Federal Republic of Germany to become a NATO member state in 1955. The Soviet Union responded with the creation of the Warsaw Pact in May 1955. The Cold War therefore had evolved from two opposing political and economic systems to two opposing military alliances. The unsettled status of Berlin caused a re-emerging of tensions when, in 1958, Soviet leader Nikita Khrushchev issued an ultimatum to the Western powers to evacuate West Berlin. Both sides however demonstrated that neither was willing to escalate to potential nuclear war. The crisis subsided with the decision to build the Berlin Wall in 1961, thus somewhat blocking the exodus from East Berlin that had caused the crisis in the first place. As the United States and the Western Europeans accepted and did not challenge the building of the Wall, it became more than evident that the division of Germany and of Europe was a reality to live with and not defy. During the 1960s, the challenges to the alliance were of a different kind. The French decision to withdraw from the alliance's integrated military structure in 1966, following President Charles de Gaulle's refusal to accept any collective form of control over his armed forces or to limit the independence of the French nuclear deterrent, exposed the first cracks within the Western Bloc. The American leadership, while obviously still very much needed and welcomed, started, however, to be increasingly questioned. On a broader scene, the emergence of the rules of coexistence and of the first signs of detente between East and West led to the approval of the so-called Harmel Report, named after Belgian Foreign Minister Pierre Harmel in 1967, formally called the Report of the Council on the Future Tasks of the Alliance. The report introduced the notion of deterrence and detente, thus setting the basis for a more cooperative approach to security issues that would come to characterise NATO in future years. The 1970s and 1980s brought to the fore yet another crucial issue, the out-of-area dilemma, that is how to deal with challenges formerly outside the territorial scope of the alliance. With the oil crises, the 1973 war in the Middle East, the Iranian Revolution, the Soviet invasion of Afghanistan and the Iranian-Iraq War, it became more than evident that, increasingly, security challenges to the alliance itself and to the alliance's cohesion were rooted in out-of-area issues. When the Berlin Wall suddenly and unexpectedly collapsed, followed by the disintegration of the Soviet Union, the Cold War, which had provided the core motivation for NATO, came to an end. As the debate on the future of the alliance emerged, some of the issues that had dominated its existence throughout the Cold War remained on the table. The perennial problem of burden sharing, the political dimensions of the alliance and the dilemma of how to deal with out-of-area issues. While during the Cold War, the need for the alliance to remain focused on the Soviet threat enabled the sidelining of these questions. In the post-Cold War era, they would pose serious challenges to NATO's continued existence.