By Paul Reynolds BBC News Online world affairs correspondent

President Bush is keeping up his bombardment of pressure on Saddam Hussein - giving a pep talk to troops at Fort Hood in Texas, telling reporters at his ranch that the "day of reckoning" is coming, and despatching the Third Infantry Division to the Gulf.

The despatch of ground troops, especially, is always a sign of real preparations.

This is a game of brinksmanship, but one which might go over the brink

It was the movement of the US army's VII Corps from Germany in 1990 which signalled President Bush senior's readiness to fight the Gulf War to remove Iraqi forces from Kuwait.

It sounds as if President Bush junior has all but made up his mind. He is certainly marching as to war.

But he is marching ahead of his British allies, who do not agree that there is yet the justification for a war.

Nor does United Nations Secretary General Kofi Annan, who says there is "no basis" for war at the moment, given the co-operation shown to weapons inspectors by the Iraqis.

War of words

War is not, however, certain.

President Bush says there is still time for Iraq to "disarm", and to get Saddam Hussein to disarm, military preparations have to be advanced.

This is a game of brinksmanship, but one which might go over the brink.

President Bush senior was in power during the last war against Iraq

It is important to note that the president has preserved his claimed right to go to war whatever the inspectors do or do not find.

He has already laid down the diplomatic barrage behind which his troops might march. As far as Washington is concerned, Iraq is already in "material breach" of Security Council Resolution 1441.

Mr Bush said about Saddam Hussein: "He put out a declaration that the world realised was false".

Yet not all the world said that. Many countries suspect it might be false, but want proof from the inspectors.

British dilemma

The American interpretation of Resolution 1441 - that a false declaration by itself constitutes a material breach - goes well beyond even that of the British.

Britain follows the language of the resolution, which requires both a false declaration and non-cooperation before a breach can be determined. So far, non-cooperation has not been proved.

US military might is building up again in the Gulf

It is not just a semantic difference. It could mean that Britain would face a difficult dilemma if the inspectors do not find the smoking gun they are looking for, even assuming one exists.

Would British Prime Minister Tony Blair join a war if the evidence is not found by the inspectors?

The chief inspector Dr Hans Blix will report to the Security Council by 27 January.

That date is not, a senior British official has said, the end of the affair, after which it is do or die.

"Do not over-hype it", he told reporters.

The resolution simply calls on Dr Blix to "update" the Council on his findings.