By Jonathan Marcus BBC defence correspondent

The United States has decided to effectively remove its signature from the treaty establishing the International Criminal Court.

The move is a highly unusual and perhaps even unprecedented step.

While signing the treaty some two years ago, President Bill Clinton did not seek Senate ratification of the agreement.

There is growing frustration at Washington's insistence that in terms of the menu of international treaties, it will dine a la carte

Critics of the treaty - especially in the Pentagon - feared that the court might be used by opponents of the United States to pursue politically-motivated cases.

With the election of President Bush, the conservative critics have been able to press their claims further.

The US is now effectively saying that it wants nothing to do with the treaty regime in any shape or form.

Short-sighted

But advocates of the court, including the governments of most of America's major Western allies, say that this is a short-sighted step - especially at a time when Washington is pushing for the broadest international co-operation in the fight against terrorism.

The Bush administration's unilateralist approach is attracting foreign criticism

Despite US opposition, the court will begin work next year in The Hague. More than 60 countries have ratified its founding treaty.

But it will be weakened without US involvement, and opponents of the Bush administration's stance have argued all along that America's support is vital if the court is to establish itself quickly as an authoritative body.

Much of the debate in the wake of this decision will not be so much about the court but about the Bush administration's whole approach to the wider international community.

There is a growing body of treaties and agreements - ranging from climate control to the banning of landmines - which the US, for one reason or another, has chosen to oppose or ignore.

And there is growing criticism of US unilateralism, even from its friends, and - above all - frustration at Washington's insistence that in terms of the menu of international treaties, it will dine a la carte and, if necessary, alone.