THE 104th Congress returns from recess tomorrow to face its most complex and politically delicate foreign-policy decision: whether to accede to President Clinton's determination to deploy 20,000 United States troops to bolster a Bosnian peace accord initialed last week.
Wary lawmakers are eager to get Mr. Clinton as far out front as possible in defense of the planned mission so that he, not they, will be blamed if casualties are incurred. But the strategy holds risks. If the mission is a success, he, not they, would likely get credit from American voters.
"I don't see how Congress can stand in the way no matter how it's voted in the past, because peace in Bosnia and US credibility in NATO are at stake," says a Democratic source on Capitol Hill.
During three weeks of intense negotiations leading up to last week's accord, lawmakers put the White House on notice that Congress would have to be consulted before US troops were committed to guarantee the peace.
But in the wake of the agreement it will not be an easy case for the administration to make.
In his weekly radio address Saturday, Clinton said "our values, our interests, and our leadership" are at stake in Bosnia. The same message will be delivered when Clinton addresses the nation on television tonight and when his top aides testify on Capitol Hill this week.
Clinton has committed at least 20,000 US troops to a 60,000-member NATO force that, among other things, will oversee the removal of warring Bosnian armies from designated buffer zones.
The area where US forces are to be deployed, around the Bosnian city of Tuzla, is considered the least hazardous of the NATO occupation zones because it has stretches of flat terrain that will accommodate the tanks and armored vehicles needed to deter truce violations.
Even so, there will be risks from land mines, snipers, and opponents of the peace who may seek to inflict casualties on US troops as a means of pressuring Clinton to bring them home.
Even if he can allay the concerns about the risks of the operation, Clinton will still have to satisfy Congress and the public on the larger question of why it is in the America's national interest to send ground troops to Europe.
When President Bush sought congressional backing during the build-up to the Gulf war, he could point to a definable enemy - Iraqi leader Saddam Hussein - and a vital US interest in protecting Gulf oil supplies. Clinton will have to rely on less tangible - and thus less salable - arguments: that US participation in the Bosnia enterprise is needed to preserve peace in Europe, US leadership in NATO, and America's standing in the world.
"Bush had a villain. What Clinton has is preserving NATO," says the congressional source. "That's why he has such a difficult role."
TO convince skeptical lawmakers, Clinton must to spell out what he meant when he told reporters last week that the US mission in Bosnia was "clear" and "achievable."
Congress will press the president on whether the applicable yardstick for success - and thus the precondition for withdrawing troops - will be the successful conclusion of general Bosnian elections, the rearming of Bosnia, or the mere preservation of peace for some minimum period of time.
If postwar history is any guide, Congress is unlikely to block US troop deployments and Clinton is unlikely to be constrained by Congress's reservations about the mission.
But in the face of heavy US casualties, lawmakers could invoke their power over the purse to restrict or terminate US involvement, as they did after 18 US soldiers attached to a UN peacekeeping force in Somalia were killed in 1993.
There are clear indications that Congress has become less deferential to the president since the end of the cold war and the election of the 104th Congress.
Under the circumstances, Clinton might be compelled to agree - formally or informally - to live with restrictions on the size of the American force or the definition of its mission.
On the other hand, lawmakers on Capitol Hill are not in the strongest position to criticize Clinton's Bosnia policy.
"The tragedy in Bosnia is that Congress has had relatively few hearings, published no staff analyses, never called the main US experts on Bosnia in to testify, and formulated no coherent policy of its own to guide the president," says Stephen Weissman, author of a new book on Congress and foreign policy entitled "The Culture of Deference.
Thus, he adds, "it's left with a kind of negative case, raising questions without any alternative conception of its own."