LEADING ARTICLE: Do not wobble over Bosnia

The application of irresistible force to an immovable object does not, at first sight, appear to be working in Bosnia. Nato air crews have now flown thousands of sorties in an aerial offensive intended to break the will of General Ratko Mladic. Yet the Bosnian Serb military overlord refuses to withdraw heavy weapons from around Sarajevo. Defying the alliance to do its worst, he also counts on the bombing to stiffen the historic spirit of Serb resistance against external foes. Meanwhile the bombs dropping on Bosnia threaten to detonate a crisis in relations between Russia and the West. General Mladic may conclude that he should dig in and play for time. What next?

To borrow a phrase from Margaret Thatcher, this is no time to go wobbly. The United Nations command in Sarajevo was right to insist yesterday that it is now in the business of peace enforcement. That means an end to bargaining with the Serbs and a determination to impose, at last, a minimum level of protection for the people of Sarajevo. Any wavering on this point would be a fatal error of political judgement.

So the focus must still be on General Mladic, regardless of the unrest in Russia and the predictable wranglings within the Nato alliance. Stripped of the encumbering United Nations bureaucracy, the allies have accomplished much in the past few weeks. They have consolidated their troops in central Bosnia and diminished the paralysing risk of hostage-taking. They have finally defined a clear set of objectives and set out to enforce them. They must now remain coherent and keep the Russians attached to the negotiations unfolding in parallel with the bombing campaign.

It would, however, be wise to take two further steps which might lead General Mladic to comply with Nato's demand. First - without easing the military pressure on him - the allies could insist that the Bosnian government give firmer guarantees not to exploit the air offensive by launching attacks around Sarajevo. That would remove a key objection by General Mladic, who insists that to pull out his heavy weapons would put at risk more than 100,000 Serbs who live in the area. Second, the Nato allies could arrange a ceasefire around Sarajevo to enable a verified withdrawal of weaponry to take place.

If neither condition sufficed, then there would seem to be little alternative to extending Nato's air attacks to the broader list of targets already defined by its planners. But nobody should be under any illusions about the dangers of the course which Nato has chosen. Its gunners and airmen are now, in effect, engaged against the Bosnian Serbs to the military advantage of the Muslims and Croats, who yesterday made significant gains in central Bosnia.

This not a policy which the governments of Britain or France will sustain for very long - nor should they. The presence of British and French troops must remain coupled to progress in peace talks. If the bombing forces the pace at which Bosnia's Serbs come seriously to the negotiating table, it will have served its purpose. Bombing the Serbs, by itself, may make some people feel better about a war which still shames modern Europe. But it is not a substitute for the political negotiations in which the United States has now taken a vital and long overdue lead.