Leading Article: West must now hold fire

THE TEST for British or combined Western military intervention abroad is that it must be conducted with a precise and achievable political objective in mind. There is nothing worse than a rush to arms that disguises a lack of clearly defined political purpose. That is why, for much of the past three years, this newspaper has expressed reservations about the wisdom of using Western military power to determine the outcome of the wars in what was Yugoslavia. Since the summer of 1991, Western policy has somersaulted so frequently - from support for a united Yugoslavia, to support for an independent Croatia and Bosnia, to support for various schemes of partitioning Bosnia on national lines - that it has seemed ill-advised to inject more force into a dangerously unstable international equation.

However, Nato's air strike last Friday on a Bosnian Serb target outside Sarajevo took place against a different political backdrop. There is now an international peace proposal for Bosnia that is accepted by all parties except the Bosnian Serb leadership. The proposal, which seeks to allocate 51 per cent of Bosnia to a Muslim-Croat federation and 49 per cent to the Bosnian Serbs, may have its flaws. But it is the first plan to gain significant broad support, including, crucially, from Russia and even from President Slobodan Milosevic of Serbia. The risk of a serious Western-Russian split over Bosnia, with all its consequences for security arrangements elsewhere in Europe, has diminished. So, too, has the risk that Mr Milosevic will throw Serbia's full military weight behind the Bosnian Serbs and provoke more trouble in Croatia and the Albanian-populated Serbian province of Kosovo.

Under these circumstances, the application of controlled Nato force under UN authority is not the rash measure that it was last February and April, when the world could not agree on what sort of post-war Bosnia it wished to see. Moreover, the Bosnian Serb seizure of heavy weapons from UN supervision last week was such a defiant gesture that it could not go unanswered without serious damage to the united front that the West and Russia have carefully built up since May.

None of this changes the fundamental truth: that Western policy towards the former Yugoslavia, because of its inconsistency and uncertainty, has failed to shorten the war by a single day. And those who think that greater Western involvement would save lives and bring the war to a swift end are almost certainly wrong. The Nato air strike last week should not be a prelude to an all-out assault on the Bosnian Serbs, nor to arms deliveries to the Muslim-Croat federation. The recently crafted international consensus on Bosnia exists only because it is predicated on the 51-49 per cent division of the republic and on the eventual removal of UN sanctions on Serbia. If the West tries now to shift the goalposts - for example, by encouraging the Muslims to take the war into what the peace proposal defines as Bosnian Serb territory - then international unity will be fractured, and we will be back where we started.

Some threats and dangers are already emerging. One is the growing pressure in the US Congress to lift unilaterally the UN arms embargo on the Muslims. Another is the pressure from conservative nationalists in the Russian parliament to force President Boris Yeltsin into a more anti-Western Bosnian policy. A third is the possibility that the Muslims will withdraw their support for the proposed division of Bosnia on the grounds it is unfair. A fourth is that the Bosnian Serbs will step up their intransigence and, in effect, dare the world to take them on. That is likely to mean increased risks for the British and other Western UN peacekeeping troops in Bosnia.

The best way to meet these challenges is for the West to stick to the plan as drawn up in May, and not to complicate the situation further by getting more deeply involved. If the arms ban on the Muslims is not lifted, then Mr Yeltsin should be able to keep his domestic critics at bay. If the Muslims maintain their support for the plan, then the outside world should be able to count on Serbia's continuing isolation of the Bosnian Serbs. But if the West tries to go beyond the plan, then it will unravel.

The most likely source of resistance is obviously the Bosnian Serb camp. But since May their position has grown increasingly precarious. Provided that outside pressure is kept up within the framework of the plan, the Bosnian Serbs will have to succumb, and the use of Western force can be kept to a minimum.