PRIME Minister John Major is coming under mounting pressure from his own supporters to step back from letting British forces become involved in a Vietnam-style conflict in Bosnia-Herzegovina.
But his government is also being criticized by United Nations sources for entertaining the idea that if the fighting in Bosnia-Herzegovina becomes too intense, British troops will be withdrawn.
Dozens of Conservative backbenchers have told Mr. Major privately that they are unhappy about his decision last week to send a naval task force headed by the aircraft carrier HMS Ark Royal to the Adriatic Sea to support British troops distributing food and medical aid in Bosnia. The move doubles to about 5,000 the number of British military personnel committed to the Balkans.
Some leading Conservatives have publicly advised Major to withdraw British troops immediately. "We have no interests in that part of the world," said Sir Jerry Wiggin, a senior member of Parliament and former defense minister. He was speaking two days after the death of a British soldier in a sniping incident in Bosnia - the first Briton to be killed since Major ordered troops there in September.
A Jan. 17 poll of Parliament members by the London Sunday Times showed that the ruling Conservative Party is deeply split on policy toward Bosnia. A quarter of the parliamentarians favored an immediate withdrawal from Bosnia-Herzegovina, and the same proportion sanctioned completion of the humanitarian aid project, regardless of casualties. The rest said British troops should be withdrawn if the number of casualties rose steeply.
Sir Geoffrey Johnson Smith, chairman of the Conservative Party's parliamentary defense committee, defended sending the Ark Royal and a flotilla of smaller ships to the area. He argued that if a British withdrawal became necessary, the task force would provide necessary backup.
But Roger Knapman, another member of Parliament who has paid several visits to the former Yugoslavia, warned the government that an open-ended commitment in Bosnia would amount to "Britain's own Vietnam."
Sir Peter Tapsell, another member of a small group of influential Conservative members of Parliament, warned Major: "The US commitment in Vietnam began with 600 advisers and ended with 500,000 troops."
Misgivings have been rising, too, on the opposition Labour Party's benches in the House of Commons. "There is a feeling that we could be drifting inevitably to a war which could last for many years," said David Clark, Labour's "shadow" defense secretary, "and there doesn't seem to be a clear political objective."
Major's problems have been sharpened by political argument between London, Washington, Paris, and other Western capitals about how to enforce a "no fly" zone in Bosnia-Herzegovina.
Major told President Bush before Christmas that enforcement might threaten the flow of humanitarian aid and jeopardize efforts by UN mediators Cyrus Vance and Lord Owen to produce a peace settlement.
Since his visit to Washington, Major has gone along with US policy, but he has tried to keep the spotlight on Britain's humanitarian aid to Bosnia.
Last week, however, Defense Secretary Malcolm Rifkind advised the prime minister that British troops desperately need backup, either as a support against intensified fighting or to facilitate a withdrawal if that became necessary. In the days leading up to the decision, British commanders in Bosnia reported 25 violent incidents in which their troops were involved.
Mr. Rifkind's announcement that the Ark Royal was heading for the Adriatic persuaded many Conservative members of Parliament that Britain's commitment in Bosnia-Herzegovina was in danger of getting out of hand.
On Sunday Rifkind said the reinforcements were "an insurance policy." He added: "The ground forces will come out either when the job has been fulfilled or when the level of risk becomes unacceptably high.
The government's talk of possible withdrawal fueled fears among UN representatives in Bosnia-Herzegovina that British resolve was weakening, and that this ran the risk of encouraging Serbian and Muslim forces in Bosnia to escalate the conflict.
"By acting alone and talking of a possible pull-out, the British may undermine the UN effort...." a UN source said yesterday. The task force that left for the Adriatic Jan. 15 includes eight Harrier jump jets, 11 Sea King helicopters, and an artillery battery.