By Linda D. Kozaryn American Forces Press Service BRUSSELS -- The North Atlantic Treaty Organization, the most successful military alliance in history, will mark its 50th anniversary at a Washington, D.C., summit in April 1999. U.S. Marines practice the "fast rope," dropping from their CH-46 helicopter to the deck of the assault ship USS Wasp during Exercise Dynamic Response 98. The exercise was designed to show NATO's ability to project strategic reserve forces into Bosnia. U.S. Navy Photo merican armed forces play a major role in the security alliance, which has served as a bulwark of international defense cooperation for nearly half a century. Since NATO's inception, U.S. service members have worked side-by-side with their alliance counterparts. Together, they've manned divisive borders during the Cold War, improved interoperability during countless multinational training exercises, and more recently, brought peace to a troubled Balkan nation. At present, nearly 7,000 U.S. troops serve as part of the NATO-led stabilization force in Bosnia. U.S. units took the lead when NATO's peace implementation force first crossed the Sava River more than three years ago. In all, tens of thousands of Americans have served as many as three six-month tours in the land victimized by ethnic strife.   In the days ahead, U.S. soldiers, sailors, airmen, Marines and reserve personnel can count on being part of future NATO peace efforts. They will work with forces from Great Britain, Denmark, Norway and other member nations, as well as with NATO's new Partnership for Peace countries -- Belarus, Lithuania, Romania and 24 more. ATO is expanding in the wake of the Cold War, opening the door to new members and taking on more partners to meet the defense needs of a new era. The security alliance was born in the wake of World War II, basically for the same reason. A Dutch soldier secures a landing zone during NATO Strong Resolve exercises in Norway. Photo by Henri Gaskjenn Having withstood Hitler's aggression, 12 Western European and North Atlantic nations joined to defend their freedom and independence from future foes. They recognized that even though the war was over, a new threat lurked on the horizon. Unlike the United States and other nations that cut military forces after the armistice, the Soviet Union maintained full military might. Soviet forces illegally blockaded Berlin and repressed democracy, freedom and civil rights in Central and Eastern European countries under their control. Eventually, the Soviets' aggressive, expansionist policy led to what became known as the Cold War. It also served, in part, as the impetus for the Brussels Treaty of March 1948. To counter the Soviet threat, Belgium, France, Luxembourg, the Netherlands and the United Kingdom agreed to develop a common defense system. Their treaty's goal was to strengthen international ties to resist ideological, political and military threats to their common security. year later, the United States and Canada agreed to form a North Atlantic alliance with the five European nations. Officials of the fledgling alliance also invited Denmark, Iceland, Italy, Norway and Portugal to participate. In April 1949, the 12 new allies signed the Treaty of Washington, and the North Atlantic Treaty Organization was born. Greece and Turkey joined NATO in 1952, followed by the Federal Republic of Germany in 1955, and Spain in 1982 for a total of 16. By next spring, the total will reach 19 when Poland, Hungary and the Czech Republic officially join the alliance at the 1999 anniversary summit. Other nations such as Bulgaria, Romania and Slovenia also seek membership, and future accession rounds are promised. Once accepted within NATO's protective circle, each nation shares the risks, responsibilities and benefits of collective security. If one member's territory is threatened, all have pledged to come to the rescue. When it comes to defense, the NATO motto is still: "One for all and all for one."   TOP