Both Houses of Congress are expected to give President Bush authority before the end of the week to use force against Iraq. This follows a methodical address by Mr Bush to the nation on Monday evening, in which he marshalled his arguments for confronting Iraq, but pledged that congressional authorisation of war did not mean "that military action is imminent or unavoidable".
The President invoked the horrors of September 11th to argue, however, that to wait "is the riskiest of all options".
As Mr Bush relaunched a drive yesterday for a tough UN resolution on Iraq by calling French President Jaques Chirac, US Secretary of State Colin Powell went to Capitol Hill to tell reporters that the congressional resolution would "strengthen my hand" at the Security Council.
America wants one hard-line Security Council resolution on new weapons inspections, but the French, backed by Russia, have called for postponing the threat of force to a second resolution later. Mr Bush continued to press his case against President Saddam Hussein, declaring at a Republican campaign rally in Tennessee that if the UN "won't deal with this man, the United States will lead a coalition of nations to disarm him - for the sake of peace."
In a key paragraph in his televised address on Monday, however, he listed conditions other than disarmament to avoid war.
"Iraq must end its support for terrorism. It must cease the persecution of its civilian population. It must stop all illicit trade outside the oil-for-food programme. It must release or account for all Gulf War personnel, including an American pilot whose fate is still unknown. By taking these steps, and only by taking these steps, the Iraqi regime has an opportunity to avoid conflict," Mr Bush said.
The congressional resolution, he said, "will tell the United Nations, and all nations, that America speaks with one voice and is determined to make the demands of the civilised world mean something".
The evidence marshalled by Mr Bush in his 30-minute speech - given in Cincinnati, Ohio, to an attentive hand-picked audience of 400 who gave him a standing ovation - was taken at face value by most members of Congress.
Democratic Senator Joe Lieberman and Republican Senator John McCain spoke out strongly in favour of giving the President war powers. "Disarm or we will be forced to go to war to disarm you," said Mr Lieberman, the former running mate of Mr Al Gore, who is against unilateral action. A minority in both Houses continued to express scepticism, however.
West Virginia Democratic Senator Robert Byrd said the resolution gave the President so much latitude that Congress might as well put up a sign that said, "Going fishing". The Congress resolution, expected to go to a vote in both Houses tomorrow evening, urges the UN to enforce strict new rules on inspecting and eliminating Iraq's alleged stores of weapons of mass destruction, while giving the President authority to act unilaterally if the UN fails to meet the Iraqi threat.
The resolution also requires the President to notify Congress no later than 48 hours after starting military action why diplomatic efforts had been inadequate.
In his address Mr Bush heaped abuse on Saddam Hussein, calling him a "homicidal dictator who is addicted to weapons of mass destruction", and a "student of Stalin" who used murder as a tool of terror and control within his cabinet, his army and his own family.
He could attack the US "on any given day" with chemical or biological weapons, Mr Bush said, alleging for the first time that Iraq might be exploring ways to use a fleet of "unmanned aerial vehicles" to target the United States.
Answering domestic critics, he said the campaign against Iraq would not detract from the war on terrorism, but on the contrary "confronting the threat posed by Iraq is crucial to winning the war on terror". If UN inspections resumed, witnesses must be allowed to leave the country with their families for interview, Mr Bush said, a clear invitation to defect that has been rejected as one of a number of "unfulfillable demands" by Russia.
There was no time to wait for final proof that Iraq's "nuclear holy warriors" had developed a nuclear capability.
Mr Bush also alleged, without giving details, that there had been high-level contacts for more than a decade between Iraq and al-Qaeda. Following his speech the White House released spy satellite photographs purporting to show an Iraqi nuclear facility extensively rebuilt since it was bombed by the US in 1998.
CIA director Mr George Tenet warned yesterday that Saddam Hussein's apparent policy of not attacking the US could change if he concludes a US-led attack was inevitable. Mr Tenet told a Congressional committee that if an attack was imminent, "he probably would become much less constrained in adopting terrorist action."