Military deployment in Gulf doubled with 50,000 extra troops

After its rejection of Iraq's weapons declaration, the Bush administration has stepped up preparations for war by authorising the dispatch of a further 50,000 troops to the Gulf region, doubling the US military presence there.

The deployment, Pentagon officials confirmed yesterday, will start early in the new year, and be complete by mid-January. The announcement came amid a series of planning meetings between President George Bush, the Defence Secretary, Donald Rumsfeld, and General Tommy Franks, the head of US Central Command, who would be in charge of an invasion to topple Saddam Hussein.

Under the plans, thousands of reservists will be mobilised, and additional tanks, warplanes and other equipment will be sent to join the substantial material pre-positioned around Iraq. Two more aircraft carrier battle groups are also en route to the Gulf, to join the two already there.

After Mr Bush's decision that the weapons inventory provided on 7 December by Baghdad fell well short of the demands of the United Nations Security Council Resolution 1441 for a complete accounting of Iraq's suspected chemical, biological and nuclear programmes, the real debate here has been whether formally to cite the omissions as an automatic trigger for a decision to go to war, or whether to wait a few more weeks.

The latter view has apparently prevailed, with top administration officials concluding that Washington needs more time to win over potential allies, and to put together a genuinely broad coalition to oust President Saddam. This in turn reassures critics at home who say the US has not yet made the case for going to war, and that if it does so, it must be under a clear UN mandate.

Despite the rejection of the 12,000-word declaration, Ari Fleischer, the White House spokesman, said Mr Bush would continue a "deliberative" approach to the crisis, encouraging the inspectors to use "every tool available" under the resolution to ferret out the truth about Baghdad's weapons of mass destruction.

US officials have been careful to note that the phrase "material breach" – invoked again yesterday by John Negroponte, the US ambassador to the UN – will not immediately set in motion the "serious consequences", a code-term for war, laid down in the resolution unanimously approved by the Security Council on 8 November. "We'll work with our partners on Council to determine the way forward," Colin Powell, the Secretary of State, said on Wednesday.

But for all the administration's keenness to go through the motions at the UN, there is a mood of resigned inevitability in Washington. A timetable is now clear for the countdown to military action, most likely in the first fortnight of February, long seen by the Pentagon as the best window for an attack.

The troop build-up, and intense US diplomatic efforts to build international support, will continue through January. Barring some blatant earlier provocation by Iraq, the next pivotal moment will come on 27 January when Hans Blix, the chief UN weapons inspector, is due to present the Security Council with his first full report on the inspections.

By then, too, the Bush administration calculates it will have again trapped President Saddam – this time on the issue of interviews with Iraqi weapons scientists, as stipulated by resolution 1441. If the Iraqi leader Saddam resists making his experts available, as Washington assumes he will, he will be in material breach for a second time. US officials claim this will harden international support for a US-led attack, clearing the decks for military action to start in early or mid-February, when weather conditions would suit a desert campaign.

Though far smaller than the 500,000 force assembled by President Bush Snr to drive Iraq from Kuwait in 1991, the 100,000-strong force – which could be easily reinforced – is in line with estimates of what will be needed for the swift, fierce campaign planned by the Pentagon. The US also wants to tighten the UN sanctions screw on Iraq, by restricting imports of antibiotics and other items, such as large tyres, which have a potential military use. But these plans, which will cause additional hardship for Iraqi civilians, could encounter strong resistance on the Security Council.