Leading article: Nato intervention is a necessity, not an option

TORNADOS, B-52S, F-117s, Jaguars, Mirages. The air power which Nato is mustering against Serbia reads like an arms salesman's catalogue. Rarely can such an arsenal have been assembled against such a small nation. The American envoy Richard Holbrooke's mission to Belgrade will need to achieve some remarkable results if it is not be used. It may produce some token concessions from the Serbs, which will tempt many to let Milosevic off the hook again.

But we should not miss this opportunity to enforce our will. Equally, we should understand why it is that we are contemplating such extreme steps. We need to be clear about why such violence against a sovereign power, which is, after all, not engaged in a war with another country, is about to be used. Why, to adapt the old phrase, are we talking about bombing this remote state about which we understand little? What are our war aims?

Well, let us recall the latest inversion of morality and the so-called "rules of war", the torture, mutilation and murder of medical staff, including Dr Lec Ukaj who had helped women having babies in the open. Dr Lec's body, with fingers hacked off, the eyes gouged out and the throat slit, was found in a ditch.

Even by the standards of the Balkans, the stories that emerge from Kosovo are grim indeed. This is an intensely cruel conflict. If even a fraction of the stories are true - and it will need forensic science and the attentions of the war crimes investigators fully to determine culpability - then they represent as clear and graphic a case for intervention as any.

So the answer "why intervene?" lies in a basic human instinct, the moral imperative to intervene to save life. Much derided by the world-weary statesmen of the Douglas Hurd school of diplomacy, the instinct to "do something" is the correct response, and militarily as well as morally.

Had we been quicker to answer the urge in Bosnia we would have been more effective, curbed the war earlier and prevented some of the suffering. We have repeated these mistakes, dithering while Kosovo burns, just as we wrung our hands during the rape of Bosnia. It is too late for those already murdered and those 250,000 people who have been forced to flee their homes. But intervention is still worth it.

The aims need to be clear. They can be simply stated: to prevent genocide; to restore peace; to avoid a humanitarian disaster and to prevent further violations of human rights. Above all, intervention will begin the process of a political settlement.

We must restore Nato's credibility. This is not just a matter of pride. It is about demonstrating our will, and, after so many hollow threats, to say to Serbia - "we will not tolerate such violence; you must make your peace with the ethnic Albanian people of Kosovo and build a lasting political settlement".

The use of military force will deter the Serbs from more brutality, and push them towards negotiations with the Kosovan leaders.

There are risks. The Serbs are a proud people with a history of defiance. There will be calls for revenge. But Serbia should be clear that the West is not advocating independence for Kosovo, or its absorption into a greater Albania - or, still less, the activities of the KLA. We merely ask that they renounce the threat of genocide, restore peace, and talk.

It is ironic that violence against Serbia is necessary to drive home the point about the importance of a peaceful settlement.

But it is necessary and, as ever, the swifter and more decisive the action, the more quickly the Balkans can be stabilised and the bleeding stanched.