SARAJEVO, Bosnia-Herzegovina — As dusk fell over a Serb-held slope overlooking this city, a U.S. Marine Corps officer poked among the hillside artillery nests to decide for himself whether, as U.N. officials were claiming, all rebel guns had been withdrawn in compliance with a NATO order.
A few days earlier, a U.S. Navy pilot passed through this Bosnian capital on a mission to scope out the effectiveness of the nightly U.S. humanitarian aid drops.
Last year, at the height of a volatile standoff between U.N.-escorted relief workers and Bosnian Serb gunmen over access to the besieged enclave of Srebrenica, two U.S. Army officers were found to be deployed there when aid workers finally pushed their way in.
Although the official U.S. position holds that no American ground forces should be sent to Bosnia, escalating U.S. involvement in the conflict gripping this republic is bringing more and more American military personnel closer and closer to the fighting.
Still, the largely clandestine U.S. role in aiding and monitoring Bosnia has not prevented the absence of significant U.S. ground troops from becoming a bone of contention with NATO allies.
Officials at the Pentagon and at U.S. European Command headquarters in Stuttgart, Germany, acknowledge that 23 U.S. officers are assigned to posts in Bosnia, and the number of soldiers working elsewhere on operations directed at the former Yugoslav federation has soared to more than 2,000 over the last year.
But the official figures seem grossly understated in comparison with the forces visible on the ground.
On the last Saturday afternoon in February, an American reporter counted 30 U.S. troops in the coffee shop at the Split, Croatia, airport, a transit point for U.N. operations in Bosnia and a relief staging area where European Command officials claim only 11 American cargo handlers are at work.
Seven U.S. Army officers were encountered on a single flight from Sarajevo to the Croatian capital of Zagreb in November, belying what was then a routine claim by Americans encountered in Bosnia that they were one of less than a handful of officers seconded from the North Atlantic Treaty Organization.
On the rural Bosnian roads traversed by aid convoys, outside the offices of Bosnian politicians and military kingpins involved in the conflict, and at U.N. listening posts around this republic that has been torn by ethnic strife for two years, U.S. forces are present nowadays.
Non-military Americans are also increasingly visible in Bosnia. One Western aid agency, in particular, hosts a number of purported American volunteers of middle age who have been spotted by journalists working in other capacities in other global hot spots, such as Central America, Afghanistan and the Middle East, presumably for military intelligence services or the CIA.
U.N. officials here and American military sources in Washington concede that an unspecified number of Americans, presumably intelligence gatherers, have been traveling throughout Bosnia to provide the information needed by the Joint Chiefs of Staff to make decisions about future U.S. involvement in the Balkan crisis.
But NATO allies complain that U.S. policy, which often differs sharply from that of the Europeans, is being made in a vacuum because it does not have to take into account the consequences for U.N. troops already deployed here.
U.S. military sources here are virtually unanimous in their opinion that American ground forces, as opposed to the eyes and ears currently deployed by Washington, should continue to stay out.
The U.S. ground presence in Bosnia is minimal in comparison to the contingents deployed by NATO allies France, Britain and Canada, which provide the bulk of the 12,000 U.N. troops now in Bosnia.
But the token American presence is the guiding force for an ever-growing network of humanitarian and observation missions that U.S. officials argue has been a more effective form of intervention in the Bosnian conflict than the U.N. Protection Force approach of sending lightly armed peacekeepers into the midst of the fighting while giving them no authority to try to stop it.
Marine Lt. Col. Mitchell Triplett, the senior U.S. liaison officer at U.N. forward headquarters here, declined to discuss details of what Americans are doing in Bosnia, except to say they coordinate the U.S. roles in operations Provide Promise and Deny Flight. Provide Promise parachutes aid to isolated Bosnian communities; Deny Flight monitors compliance with the "no-fly" zone that the United Nations has imposed over Bosnia.
The chief task of the U.N. mission in Bosnia has been to provide protection for humanitarian aid convoys struggling to make their way through ubiquitous war zones to bring food, medicine and other relief goods to the 2.7 million Bosnians dependent on outside help. That figure represents the vast majority of Bosnians still in this republic, where industries, farming and normal transportation routes have been destroyed by the 2-year-old war.