Twenty-six years ago today, on March 12, 1999 (January 25, 1999 in the lunar calendar), Poland, the Czech Republic and Hungary joined NATO. On March 12th, 1999, the North Atlantic Treaty Organization held a ceremony at Truman Library in Independence City, Missouri, USA, formally accepting Poland, Hungary and the Czech Republic as its new members. On the same day, US Secretary of State Albright, Czech Foreign Minister Jan Kavan, Hungarian Foreign Minister Maurtoni Janos and Polish Foreign Minister Bronislaw Geremek (from left to right) were at the ceremony when Poland, Hungary and Czech Republic officially joined NATO. In order to expand its strength, the United States has pieced together military and political blocs in Europe. In April 1949, representatives of the United States, Britain, France, the Netherlands, Belgium, Luxembourg, Canada, Norway, Iceland, Portugal, Italy and Denmark signed the North Atlantic Treaty in Washington. The Convention stipulates: "Collective defense". When a country is "armed attacked", other contracting parties should "take actions deemed necessary, including the use of force". When the treaty came into effect in August 1949, the North Atlantic Treaty Organization was established, also known as the "North Atlantic Alliance" or "North Atlantic Bloc", or "NATO" for short. At the beginning of its establishment, there were 12 members, and then it was expanded four times. In 1952, Greece and Turkey joined; in 1955, the Federal Republic of Germany joined; in 1982, Spain became the 16th member of NATO. After the end of the Cold War, NATO decided to expand to the former Warsaw Pact member in January 1994. In March 1999, Poland, the Czech Republic and Hungary joined NATO, completing NATO's first expansion after the end of the Cold War. In April of the same year, the NATO Washington Summit formulated the "Accession Action Plan" and decided to continue to attract Central and Eastern European countries to join the military bloc. Seven countries, including Romania, Bulgaria, Latvia, Lithuania, Estonia, Slovenia and Slovakia, will formally join NATO this year, which will increase the number of NATO members to 26.