There is this growing perception that the Bush administration is much more interested in pursuing a unilateralist foreign policy that puts the United States first

But Iraqi armaments discovered after the Gulf War proved that the 140-nation treaty had been no deterrent - and steps were taken to rectify the situation.

By rejecting the draft agreement on enforcing the germ warfare treaty, the US seems to have effectively killed off a painstaking negotiating process that has taken 10 years to complete.

US Senator Sam Nunn - a former head of the American Senate's Armed Forces Committee - has just been monitoring an exercise simulating a biological germ warfare attack on US soil.

He says the potential threat from biological weapons is devastating.

"Biological weapons would pose a serious national security threat that would be unique and one that we are not now organised for in government or prepared for," he said.

The Bush administration is sceptical about a whole range of accords

"We found a lot of deficiencies, a lot of terrible dilemmas, and a lot of painful trade-offs that would have to be made. We have to recognise that the whole world would be involved - we have to be prepared to have enough vaccine to deal with these on a worldwide basis."

Mr Nunn, a Democrat, says he is uneasy about President Bush's rejection of the draft treaty without offering any clear alternatives.

The administration's objections centre around the fear that inspections would compromise the necessary secrecy that surrounds legitimate pharmaceutical companies as they develop new commercial drugs.

The BBC's Nick Childs says the proposed inspection procedure has proved controversial.

"Essentially it is a protocol, for those signing up to it, declaring their main facilities that could prossibly be used for developing biological weapons and agreeing to an inspection process," he said.

"The problem, as far as the Bush administration is concerned, is that they fear that this would be used to spy on their installations - but it wouldn't be able to stop genuine cheaters, because biological weapons are very easy to hide, so the detractors say you wouldn't find anything anyway."

Scepticism

The US is the only one of 56 countries engaged in the talks that has publicly refused to sign the treaty. Other participants acknowledge problems but insist that, given the trouble finding an agreement, this is at least a start.

Nick Childs says it is significant that once again the Bush administration finds itself alone in its stance, following rows about the Kyoto treaty on climate change and the existing treaties on nuclear proliferation.

The problem is that there is this growing perception that the Bush administration isn't really interested in, and has a great deal of scepticism about, a whole range of international accords on arms control and environment, and it is much more interested in pursuing a unilateralist foreign policy that puts the United States first.

Officials in Washington deny this. But the evidence is piling up and the Bush administration has not been able to produce a coherent set of alternatives to a treaty which a lot of their allies remain very wedded to.