The bellicose talk in Washington about a pre-emptive strike to topple Saddam Hussein masks a furious debate inside the Republican party.
Its outcome will determine the fate not just of the Iraqi dictator, Saddam Hussein, but probably also of the system of managing international relations that has operated for half a century. It boils down to this: can America act unilaterally, or must it first win the support of allies and the blessing of the United Nations?
That President Saddam should be removed is accepted on all sides. The question is how – and the argument lays bare the familiar fault line within the Bush administration. It divides the unilateralist hawks, led by the Vice-President, Dick Cheney, and Defence Secretary, Donald Rumsfeld, from more cautious moderates, led by the Secretary of State, Colin Powell, and embracing the military brass and a host of Republican foreign policy mandarins, including James Baker and Brent Scowcroft, Secretary of State and National Security Adviser respectively to the first President Bush during the 1991 Gulf War.
The hawks base their argument on America's overwhelming military might. On its own, the US can defeat Iraq with no trouble; and once it makes clear it is going to do so, other countries will fall into line. Going through the UN and trying to secure the return of weapons inspectors just plays into the hands of Saddam, the master prevaricator.
Don't worry about the doubters – says Mr Rumsfeld – they wobbled before the 1991 Gulf War, before the 1999 Kosovo war, and before last year's campaign in Afghanistan. Yet each time, American power swept all before it, with minimal casualties. The same will happen in Iraq, sending beneficial shockwaves throughout the Arab world and beyond.
The moderates share the basic premises of the hawks. They agree President Saddam is a menace to his region, that he is in violation of a clutch of UN resolutions, that he has used weapons of mass destruction before, that is he pursuing them now and that, should he obtain a nuclear weapon, he will employ it as a means of blackmail. While it is hardly likely that President Saddam would attack the US directly, they acknowledge that he could quietly make such weapons available to al-Qa'ida or other terrorist groups.
What worries them is the aftermath if the US goes it alone. Mr Baker frets about the damage to America's international image and traditional alliances. General Scowcroft warns of a tide of anti-Americanism, and damage to the prospects of an Arab-Israeli settlement and to the anti-terror coalition.
Both insist a new mandate from the UN, or at the very least a sincere effort to obtain one, is needed before the US goes to war. General Powell shares these concerns, though he has yet to voice them in public.
Which leaves the man who must make the fateful decision: President Bush himself. There can be scant doubt his instincts are with the hardliners. He never wastes an opportunity to call for "regime change", the euphemism for military intervention in Iraq. He knows that war has been the reason for his sky-high approval ratings, lower now but still healthy. He knows also that to climb down now would damage his credibility and hand a moral victory to President Saddam.
But even Mr Bush's tin ear for what he scornfully dismisses as "the nuances" must be alive to the problems that would follow even a successful US intervention: a new surge of anti-Americanism, fuelling the hatred of Islamic extremists and would-be terrorists, the need for not just the "nation-building" that Mr Bush detests in Iraq, but for a physical American presence in Baghdad, probably for years.
And can the sputtering US economy withstand the surge in oil prices certain if, as President Hosni Mubarak of Egypt warns, the entire Middle East descends into chaos? Reassurances on oil supplies were almost certainly Mr Bush's priority in his talks last week with the Saudi government.
Against the odds, the moderates may win the argument and prevail upon Mr Bush, for once, to eschew black-and-white and accept the world for the grey thing it is.
The message from Capitol Hill
James Baker Former secretary of state
"Seeking new [UN] authorisation now is necessary, politically and practically... We should try our best not to go it alone, and the President should reject the advice of those who counsel doing so."
Dick Cheney Vice-President
"The risks of inaction are far greater than the risks of action... And the entire world must know that we will take whatever action is necessary to defend our freedom and our security."
Donald Rumsfeld Defence Secretary
"It was not until each country got attacked that they said: 'Maybe Winston Churchill was right. Maybe that lone voice expressing concern about what was happening was right.'"