BRITAIN is ready to use the full weight of its military power to

ensure the safe withdrawal of its 3000 peacekeeping troops from Bosnia,

Defence Secretary Malcolm Rifkind said yesterday.

Speaking on the eve of a visit to Sarajevo today, he said that the

lives of the UK units committed to the United Nations Protection Force

in Bosnia -- including 750 men of the Royal Highland Fusiliers -- was

the paramount concern.

Asked about the problem of extricating the men, if the Serbs or other

combatants decided to dispute their pull-back, he said: ''Although it

would be difficult, we have considerable military assets available both

within Nato and elsewhere to ensure that withdrawal would be carried out

comprehensively.''

But he added that any escalation of the fighting which would make

Unprofor's position in the country untenable would be ''a huge step

backwards'' in terms of safeguarding lives and providing humanitarian

aid.

He also criticised the Nato policy of threatening bombing raids as its

sole response to Serb or Muslim aggression. ''By bombing isolated sites

or targets, one can only exacerbate the situation,'' he said.

''You cannot stop what is essentially a civil war by bombing. No

conflict in history was ever decided by air power alone. But we will do

whatever is necessary to protect our troops should the need arise.''

Mr Rifkind's visit to Bosnia will be his fifth to the war-torn former

Yugoslavia. He confirmed yesterday that he will meet the UN's senior

commander, Lieutenant-General Sir Michael Rose, during the trip for

discussions on the future of the peacekeeping mission.

Lieutenant-General Rose is currently trying to persuade the Bosnian

Serbs to free hundreds of his men taken hostage last week as a

bargaining chip and in some cases human shields against Nato air raids.

Serb forces have launched a major offensive against the UN-designated

''safe haven'' of Bihac in north-western Bosnia. More than 1200

Bangladeshi UN troops are trapped in the shrinking pocket held by the

remnants of a routed Bosnian Muslim army.

Mr Rifkind repeated yesterday that he opposed the US-sponsored plan to

lift the international arms' embargo on the Bosnian Muslim forces. He

admitted that all sides in the conflict had been receiving smuggled

weaponry, but stressed that this was mostly in the form of small arms

and light equipment.

He said: ''Large-scale deliveries of arms would make the entire UN

position intolerable. Although it would take weeks or perhaps even

months for the Muslims to secure deliveries of tanks and heavy

artillery, the Serbs would be highly unlikely to remain inactive until

it happened.

''The most likely scenario is that they would attack in full strength

to preempt such a move. That could only escalate and spread the conflict

with disastrous results for everyone. It would certainly spell the end

of the UN's involvement.''

Foreign Secretary Douglas Hurd is due to fly to Belgrade today on what

is now widely-regarded as a forlorn diplomatic mission to persuade the

Serbs to cease their offensive and return to the negotiating table

rather than the battlefield.

In the meantime, Bosnian Serb leader Radovan Karadzic has said that

any military action by Nato will signal the start of an all-out war.

Serb missile batteries have been put on full alert, and Nato warplanes

policing the ''no-fly zone'' over central Bosnia declared legitimate

targets.

Defence sources say a scheme for the rapid withdrawal of more than

10,000 British and French troops in Bosnia is being refined by a

joint-nation planning cell at the British Army's UK Land Forces

headquarters at Wilton, Wiltshire.

The cell has been ordered to complete its detailed proposals on the

basis that the politicians will approve evacuation within the next three

weeks. Britian's original timetable envisaged withdrawing its forces

next March.

Serb intransigence and the reduction of the effectiveness of air cover

because of seasonal low cloud has now accelerated the need for a

decision.

Britain has troops based further north inside Bosnia than any other

national contingent. Their escape route lies down 150 miles of

mountainous roads which exposes them to the constant threat of ambush or

shellfire.

It is believed that a major part of the 60,000-strong Allied Rapid

Reaction Corps might have to be used to seize key features on high

ground dominating the line of retreat to the Croatian coast to allow the

peacekeepers safe passage.

If that happens, then US ground troops would have to be committed to

the area for the first time since fighting broke out three years ago.

Nato is also understood to have asked the Germans to provide Tornado

fighter bombers to help cover a withdrawal.

The German constitution was altered earlier this year to allow its

forces to serve abroad for the first time since World War Two.