FOR 40 years, soldiers belonging to the North Atlantic Treaty Organization (NATO) vigilantly watched the massed forces of the Warsaw Pact on the other side of the West German border.
But now the cold war has ended, the Warsaw Pact has ceased to exist, and the United States has elected a president who has pledged to reduce its troop presence in Europe.
What does this mean for the future of NATO, generally regarded as one of the most successful peacetime alliances in history? In the near term, not much. Although President-elect Clinton has pledged to reduce United States forces in Europe to a new postwar low, he has repeatedly affirmed his support for NATO and America's continuing commitment in Europe.
"The level of forces is less important than what it signifies," says Robert Hunter, director of Western European studies at the Center for Strategic and International Studies in Washington. "The broader concern is the overall US commitment to European security. And both Bush and Clinton are strongly committed. So NATO will prosper under a Clinton administration."
But even if NATO survives, it is far from clear what form the alliance will take now that it has lost its original raison d'etre: preventing a Soviet invasion of Western Europe.
Arguably the first challenge for a post-cold-war NATO is defining the threat it is supposed to meet. That has not proven easy.
Think-tank analysts, military officers, and political leaders have been scratching their heads to come up with a variety of possible scenarios that would require a military response from NATO, ranging from an all-out attack by a resurgent, fascist Russia to a major civil war in Eastern Europe to a new Middle Eastern crisis.
Privately, some Europeans are concerned that, without NATO, Germany's conventional and nuclear forces would destabilize the continent. Above all, NATO leaders say, the organization is needed as an "insurance policy" against unknowable "uncertainties" that could plague Europe.
"As the certainty of the Soviet Union faded, it left behind unresolved disputes that we see now in Nagorno-Karabakh [the Armenian-populated enclave in Azerbaijan], in the former Yugoslavia, and in Georgia. It left behind religious strife and economic collapse," Gen. John Shalikashvili, the supreme Allied commander in Europe, said last year. "It's those uncertainties, those unpredictabilities that threaten us today."
NATO already has started to reorganize itself to deal with new threats. Last October, the alliance launched a rapid-reaction force that is supposed to field 80,000 soldiers by 1995.
Earlier in 1992, NATO's foreign ministers decided to allow its forces to be used for peacekeeping missions outside of Western Europe. The first deployment in that role came in November, when NATO warships started enforcing a United Nations embargo of Yugoslavia.
NATO's greatest enemies as it seeks new missions may not be its former adversaries in the East but, rather, competing Western European organizations.
France, in particular, has been pressing for the creation of a security structure in Europe that excludes the US. This has led to the birth of a Franco-German Corps; it also accounts for the sudden revival of the long-dormant Western European Union (WEU), the defense arm of the European Community (EC). WEU warships are patrolling alongside NATO vessels in the Adriatic Sea.
Nevertheless, there are strong indications that NATO will continue to play a central role in European affairs.
The WEU is still weak, and the rush toward integration appears to have slowed after the Maastricht Conference (the EC's 1991 summit).
Most of the Western European countries, especially Britain and Germany, have said they want US forces to remain stationed on the continent. And some Eastern European nations, such as the Czech Republic and Hungary, have expressed an interest in joining the Atlantic alliance.
"The Europeans want NATO to continue because it's the symbol and the fact of US military commitment to the security of Europe," says Andrew Pierre, a senior associate at the Carnegie Endowment for International Peace in Washington. "For the moment, few Europeans or Americans are calling for a total US pullout."
But the question remains: What size commitment should the US make to post-cold-war NATO? Currently, there are 206,000 US troops in Europe, down from 317,000 two years ago. President Bush has proposed reducing the number to 150,000 by 1995, but Mr. Clinton says he will keep only 75,000 to 100,000 troops assigned to NATO.
But a RAND Corporation report prepared by analyst Richard Kugler for the secretary of defense suggests that 150,000 troops is the mininum number required to preserve a meaningful political and military role for the US in Europe. Seventy thousand soldiers would be a commitment only, while a force of 100,000 "would be `hollow' in important ways," Mr. Kugler's study concludes.
Cost, analysts say, is not a major factor in deciding how many US soldiers to keep in Europe. Lt. Ken Satterfeld, a Pentagon spokesman, says that keeping 150,000 soldiers in Europe costs about $20 billion annually, but that bringing them home would save just $5 billion - a drop in the bucket of the armed forces' budget.