The negotiations culminated in the signing in April 1949 of the Washington Treaty, which established a common security system based on a partnership between 12 countries: Belgium, Canada, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal, the United Kingdom and the United States. In 1952, Greece and Turkey joined the treaty. In 1955, the Federal Republic of Germany joined the Alliance, and in 1982, Spain became a member of NATO. The Czech Republic, Hungary and Poland joined NATO in 1999. Bulgaria, Estonia, Latvia, Lithuania, Slovakia, Slovenia and Romania joined NATO in 2004. Croatia and Albania became members in April 2009. Montenegro became a member in 2017. When the power of the Soviet Union spread to several Eastern European countries, Western European countries feared that Moscow would impose its ideology and authority throughout Europe. Since the end of World War II in 1945, Western governments have begun to reduce their defence facilities and demobilize their armed forces. In January 1948, however, British Foreign Minister Ernest Bevin spoke of the need for an “alliance and mutual assistance,” a defence alliance and a regional grouping under the Un Charter.
On 26 March, representatives of NATO countries signed accession protocols that would allow Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia and Slovenia to join NATO as changes to the North Atlantic Treaty after ratification. On 29 March, NATO formally integrated Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia and Slovenia into its largest enlargement to date. Membership was the fifth since the creation of the Alliance and brought its membership to 26 countries. Membership was followed on 2 April by a flag ceremony. Secretary General Jaap de Hoop Scheffer had asked the seven countries to become members on 2 March, after each of NATO`s 19 member countries informed the United States of the adoption of protocols annexed to the North Atlantic Treaty. On 17 December, the North Atlantic Council met at the level of the Minister of Defence, with the participation of the three invited countries, the Czech Republic, Hungary and Poland. There were ministerial meetings of the Defence Planning Committee and the Nuclear Planning Group. Ministers approved the 1998 ministerial guidelines that provide policy direction to NATO military authorities for the period up to 2006 and beyond. The accession protocol was signed in May 2016 and Montenegro became a member of the Alliance on 5 June 2017. In 1944, Harry Truman ran for vice president on the Democratic ticket with President Franklin Roosevelt. He was sworn in on January 20, 1945.
82 days later, he became the 33rd president when Roosevelt died suddenly. In his new role as President of the United States, he contributed to the end of World War II and the opening of the new post-war world.