Of all the crises in the former Yugoslavia that could trigger a U.N. withdrawal, war in Croatia and the threat of Yugoslav army involvement tops the list for worried Western military planners.
Yet however it begins, they warn, withdrawal could be worse than any fighting to date."Any kind of withdrawal operation is going to be an absolute mess," U.S. Adm. Leighton Smith, NATO's southern European commander, said in a recent interview at his headquarters in Naples, Italy. "We have a number of situations that we've tried to game out, to consider how you deal with them. None of them are easy; every single one hard or complicated."
Politicians have made no decision to withdraw 24,000 peacekeepers from Bosnia and perhaps 12,000 more from Croatia. But they have asked NATO to make plans.
The result has been a dismal picture of battles for U.N. posts and weapons, hysterical women trying to block withdrawal and civilians being slaughtered once the United Nations leaves.
Many of the feared scenarios already have occurred, with the fall of the U.N. "safe areas" of Srebrenica and Zepa in Bosnia and the refugee exodus following Croatia's offensive against Serb rebels.
"We have had a preview, but it's a preview in micro," said one NATO official, looking at a photo of a Bosnian woman who hanged herself with a blanket after fleeing Srebrenica.
If newly confident Croats attack eastern Serb-held areas of the country, the Yugoslav army would likely be drawn in, "letting loose the dogs of war" and unquestionably ending the U.N. mission in Croatia, said one senior NATO officer. Leaving Croatia, the U.N. operations headquarters for former Yugoslavia, would surely doom the Bosnian mission as well, NATO officials said.
Lifting of the arms embargo on Bosnia, large-scale airstrikes against the Serbs, or a move to divide Bosnia between Croatia and Serbia also could lead to with-drawal.
NATO has not publicly presented its 1,500-page "Operation Determined Effort" withdrawal plan, but officials discussed details on condition they not be identified.
Up to now, planning had focused on Bosnia while U.N. troops stayed in Croatia. Leaving Croatia, too, would complicate the mission, although that would probably not significantly increase the estimated 50,000-60,000 troops needed.
NATO has been working with Croatia for months, installing an independent communications system, and surveying roads and ports. If the Croatian ports of Split and Ploce were no longer a staging ground, NATO would have to rescue U.N. forces by air. That is particularly risky in Bosnia, where surface-to-air missile sites abound.
Air rescue also would force the abandonment of some 8,000 U.N. vehicles of the multinational force, plus 3,000 tanks, armored personnel carriers and motorized artillery, and up to 13,000 containers of supplies. Weapons and munitions would have to be destroyed, one NATO official said.
Plans call for pulling peacekeepers out in "armored slugs," convoys protected by heavy air cover as they trek through Bosnia to Croatia and the sea - a process expected to last at least six months. That would be more complicated in winter, but NATO insists a winter withdrawal is possible.
NATO is also confident it can deal with local troops trying to interfere. It is the women and children left behind who give planners nightmares.
NATO plans only limited humanitarian aid to civilians and protection only in cases of "direct, imminent and egregious human rights violations." Planners are considering high-tech crowd controls, such as foam spray retaining walls, and psychological operations including airborne radio stations and leaflet drops.
Still, NATO officials are wary of being kept in Bosnia beyond the withdrawal.
"I'm not convinced we would walk off and leave a humanitarian disaster," said one NATO planner. "I don't think morally and in good conscience we could abandon people who are starving."