ComeJune, the American troops helping to maintain peace in Bosnia are scheduled to come home. Recently, however, some senior adminis tration officials have begun murmuring about staying on longer. "A consensus is developing," says Secretary of State Madeleine Albright, "that there will be or should be some form of U.S. military presence" after the current force leaves. "If we pull out on an arbitrary deadline," says the architect of the 1995 Dayton Accord, Richard Holbrooke, "the situation in Bosnia will become chaotic, eroding the achievements so far." Such talk does not sit well with Congress, where many were hos tile to the original mission and outraged at its first extension last year. The stage is set for a battle this spring over U.S. policy in Bosnia. The administration and Congress do seem to agree on one impor tant issue: any new Bosnia mission must have an "exit strategy." In her confirmation hearings, Albright assured Senate questioners that she "would never advise using American forces . .. where there is no exit strategy." In his confirmation hearings, Secretary of Defense William Cohen explained that before deploying troops he would ask questions such as, "Do we have a so-called exit strategy? We know how to get in. How do we get out?" In 1996 then-national security adviser Anthony Lake even crafted an explicit "exit strategy doctrine," which had as its centerpiece the principle, "Before we send our troops into a for eign country we should know how and when we re going to get