M.A.S.H. Hospital in Zagreb Gives U.S. Army a Role in Balkans : Intervention: First patient is treated even as unit is setting up for casualties among U.N. peacekeepers.

It took the U.S. Army only five days to erect a sprawling field hospital at Zagreb Airport, yet before the soldiers could change from coveralls to scrubs, they were confronted with their first emergency.

A Croatian bulldozer driver working under contract with the Mobile Army Surgical Hospital, or M.A.S.H., stumbled over a land mine buried by the Yugoslav People’s Army when it beat a hasty retreat from the Croatian capital more than a year ago.

The injury, swiftly dealt with amid the deafening roar of forklifts and generators, served as an ironic reminder that the U.S. forces themselves may be entering a political booby trap.

Until President Bush’s decision two months ago to dispatch the M.A.S.H. unit to treat casualties from among the 22,000 U.N. peacekeepers deployed to Croatia and Bosnia-Herzegovina, Washington had kept the raging Balkan crisis at arm’s length.

By sending a medical team rather than infantry as its contribution to the expanding mission, the Pentagon continues to keep its distance from the bloody fratricide that has already killed tens of thousands.

But the size of the new medical facility and the United States’ belated intervention in the crisis have raised eyebrows among Croats, who are increasingly opposed to the U.N. mission, which they see as serving to protect Serbian interests at the expense of Croatia.

“UNPROFOR, go home!” was the rallying cry of a far-right political party during an election campaign last summer, and even the ruling Croatian Democratic Union has widely hinted that the peacekeepers’ mandate will not be renewed when it expires in March.

The growing resentment of the Croatian population toward the U.N. mission could expose the U.S. troops to acts of civilian hostility.

Also, some Western diplomats warn that Washington’s back-door approach is sending mixed signals. Positioning troops at the edge of the conflict sets the precedent for deeper U.S. involvement, while demonstrating a reluctance to take a leading role in resolving the crisis.

Having arrived in Croatia only two weeks ago, the M.A.S.H. commanders say they are unable to estimate how long they will be needed here, and they are unwilling to speculate whether the sizable capacity of the hospital signifies that the U.S. government expects an escalation in U.N. casualties.

Now up and running, the M.A.S.H. unit quickly picked up five patients: two broken bones incurred in car wrecks, a case of skin rash, and two soldiers with leg wounds inflicted by land mines.

Fighting is not as heavy since a shaky cease-fire took effect two weeks ago, but few see the conflict as over.

“I think we’ll be relatively busy. They don’t send a 60-bed M.A.S.H. for three or four patients,” said Maj. Ken Fugett, spokesman for the mobile hospital that has been temporarily relocated here from its base in Wiesbaden, Germany.

The terms mobile and temporary are relative in this case. Those who erected the elaborate network of tents, heating systems, computers, phones and medical equipment say it was a herculean effort to meet the Nov. 15 deadline for being patient-ready. No one expects to decamp in the foreseeable future.

The M.A.S.H. unit’s current mandate is for a six-month stay, which would keep the 350 doctors, nurses, technicians and support staff in Croatia until mid-May. That is two months beyond the approval for UNPROFOR--an acronym for U.N. Protection Force, the troops assigned to Croatia and Bosnia-Herzegovina, which is already the largest peacekeeping operation the United Nations has ever launched.

The mere presence of U.S. soldiers has raised both fears and expectations.

At an opening ceremony for the M.A.S.H. unit, U.S. Rep. Frank McCloskey (D-Ind.) hinted that the United States and other Western countries have decided to take a tougher line against Serb-dominated Yugoslavia, which has been blamed for fomenting violence both in Croatia and Bosnia.

“Western policy based on negotiations, sanctions and peacekeeping has failed,” McCloskey stated. “We need a more forceful and coherent strategy which confronts, instead of acquiescing in, Serbian aggression.”

Noting that concentration camps continue to operate in Bosnia and that ethnic violence now is also threatened in the Serbian province of Kosovo, McCloskey said he is urging both Bush and President-elect Bill Clinton to lift the arms embargo against Croatia and Bosnia, authorize selective air strikes to deter further Serbian sieges of civilian communities and bring war-crimes charges against Serbian President Slobodan Milosevic and his proxies in the battle zones of other republics.

Some Croats are encouraged by what they see as the first steps toward U.S. intervention.

“Politically speaking, it looks like the Americans want to get seriously involved for the first time in what is going on in Bosnia and former Yugoslavia in general,” said Vesna Skare, spokeswoman for Croatian President Franjo Tudjman.

Croatian media, however, have expressed concern that the huge medical complex foreshadows an extension of the U.N. mission beyond March.

Zagreb authorities went along with the deployment in hopes that the more than 200,000 Croats displaced by last year’s fighting would be assisted by the United Nations in returning to their homes. But the peacekeepers’ presence so far has served to solidify Serbian control over the one-third of Croatian territory from which non-Serbs have been expelled.

Western diplomats in Zagreb warn that U.S. association with the increasingly resented U.N. mission could expose U.S. soldiers to acts of hostility by civilians.

“We should be prepared for the possibility of casualties, because it’s going to happen, and it will be too bad that we didn’t plan for it better,” said one envoy, who believes that the U.N. operation will continue to grow and that U.S. troops will eventually be engaged in the Balkan conflict.

Some national contingents taking part in the U.N. mission, including those from Canada and the Netherlands, have already advised their troops to stay out of public places where alcohol and firearms are both at hand, to avoid confrontations with civilians.

Lt. Col. Everett W. Newcomb III, a New Jersey cardiologist who heads the M.A.S.H. medical staff, said there have been no special restrictions issued to the U.S. troops in light of the social risks. But he said the M.A.S.H. personnel had all been extensively briefed on the crisis, the U.N. mission’s image in Croatia and the need for vigilance when mingling with the locals.

“They’ve all been told they will very likely be approached by Croatian citizens who will have very strong opinions about the nature of this war,” Newcomb said. “They have not been told to avoid talking to Croatian citizens but that they need to be very sensitive to potential problems.”