THE BEST way to support British servicemen in the Kosovo campaign is to pull them out and bring them home. They are risking their lives to redeem the crimes and mistakes of political leaders. They are struggling to make sense of the paradox of war, as they try to save lives by slaughter and pound hatred into the ground. While they are committed to combat, of course, no hesitancy at home, no frailty of command must be allowed to endanger them. War, once joined, must be fought with resolution. But that does not mean that war, in the present case, is justified. The call to support our servicemen should not exempt civilians from sanity or politicians from condemnation. We owe "our boys" solidarity in their sacrifice - and candour in denouncing the folly that demands it of them.

Mistakes can be well intentioned and crimes mitigated by honourable ends. In some ways British interference in Kosovo is admirably inspired: genuinely disinterested, vengeful only on behalf of the victims, violent against the aggressors, biased on behalf of the weak against the strong. The policy of the Yugoslav government towards its Albanian subjects is breathtakingly vicious. Its effects, when complete, will include the extermination or forced migration of hundreds of thousands of people, beyond the many thousands already dead, dying or in flight. It is right to try to stop it. War, however, is the wrong method: wrong in law, wrong in practice.

The Nato action is wrong in law because it is contrary to the purposes, terms of reference and historic code of the alliance. Nato was formed 50 years ago as a bulwark against the Soviet Union. It was never supposed to behave as a self-constituted posse of international vigilantes. In shedding blood in the present conflict it is acting ultra vires. Nato saw off communism without firing a shot. Now, ironically and grotesquely, the allies are bombing people who pose no threat to Western security. It may sometimes be necessary, as a last resort, to mobilise international forces to defend the defenceless, enforce justice and thwart tyranny. But only a genuinely neutral and virtually universal organisation can be trusted to say when. In today's world, the United Nations, with all its faults, is the only such organisation we have, and the only global guardian backed by international law.

Apologists for the bombing say there is no other way to stop Serb aggression in Kosovo. They are wrong. The Nato powers have shown little understanding of the historical background against which a diplomatic solution might be framed. Serbian brutality in Kosovo is not the result of some collective moral deficiency on the Serbs' part. Recent history has made them feel isolated and insecure. They have a deep emotional investment in Kosovo - where they regard the soil as sanctified by the blood of Serbian martyrs. If the inviolability of present frontiers in the region were genuinely guaranteed, feelings of insecurity would subside and the Serbs would be more likely to let their neighbours live in peace. A third way for Kosovo could be found, between subjection and secession. In the meantime, the Albanians of Kosovo need more diplomatic efforts on their behalf and more humanitarian aid in their plight.

All war is evil, but Nato's attack on Yugoslavia is worse than that: it is a mistake. The longer the bombing continues, the less easy it is to believe that it will bring peace to the Balkans. On the contrary, all the indications are that it will make things worse. Bomb bursts provide the perfect cover for death squads. They inspire ethnic cleansers with a sense of urgency. Moderate voices in the region are inaudible over the roar of the jets. With every new cause of vengeance, every new incitement to hatred, peace edges further away. There is nothing like a bomb to induce the mentality of the bunker. The destruction of Yugoslavia's infrastructure and industries will take a long time to wreck the Serbian war effort; but the innocent are already dying. Bombs will multiply the "humanitarian disaster" Nato claims to want to avert.

The armchair generals have said all along that bombing would fail. Now they will step up their demand for the deployment of ground troops. But that would be to throw more good lives after bad policies. The best we can hope for now is that, having tired of purposeless bombing, Nato will declare a victory, call off the attacks and enter into negotiations. It's the Anglo- American way.

Nato has blundered into war. Neither Bill Clinton nor Tony Blair gives much evidence of confident purpose, and nothing suggests that the British or the Americans are enthusiastic about the latest geopolitical whims of their leaders. In his address to the nation on Friday night, the Prime Minister said that attacking Yugoslavia was "simply the right thing to do" and that to have done nothing would have shown "unpardonable weakness". In fact, the alternative to military action is not "nothing". At a time when east and south-east Europe are crowded with frontiers bristling with inter-communal hatreds and stained by spasmodic blood-letting, the alternative is to support pluralist politicians, to stimulate economic growth, to disarm resentment, to nurse prosperity and to give traditional enemies a common interest in peace. And to try again with each failure. To reject diplomacy in favour of aggressive war is, to paraphrase the Prime Minister, simply the wrong thing to do. It will gain us, and the Kosovars, nothing.