At the United Nations headquarters you would never guess there was a war going on in the Balkans.

There are no meetings of the UN Security Council or General Assembly and no talk of any kind of UN involvement.

Put bluntly, the UN has been utterly sidelined by the whole Balkan crisis. The question many people are asking therefore is why has the UN become so irrelevant.

The short answer is the lack of consensus among the UN's five great powers and permanent security council members, the United States, France, Britain, Russia and China.

Divisions

When the problems in Kosovo resurfaced towards the end of last year, both Russia and China made clear they would not support any Security Council backing for the use or even the threat of the use of force against Belgrade.

Kofi Annan played a masterstroke of diplomacy

Faced with a potential veto by either Russia or China or both, the solution for the West was obvious if not ideal - deal with the problem in the Nato context where Moscow and Beijing do not enjoy veto powers.

Such a solution could however have profound consequences for the UN and may in the future be looked back on as a defining, if depressing, moment in the organisation's history.

Just how bad will depend on whether it is still possible to rebuild some kind of consensus within the Security Council, or whether Russia will now oppose the US on every UN-related issue.

Much will also depend on Washington's readiness to invest some diplomacy and hard cash at the UN after the last few years of neglect and non-payment.

Diplomatic caution

The current crisis in the Balkans has also focused attention on the role of the Secretary-General Kofi Annan.

After the bombing started he issued a statement that was a masterstroke of diplomatic caution, saying that while force was sometimes needed to achieve peace, it is always better to have UN endorsement before using it.

Since then journalists have been bombarding Mr Annan's spokesman with the same basic question, "Is the Secretary General going to mediate in the conflict?"