President Bush failed over the summer to provide enough hard evidence of Iraqi support for Al Qaeda to justify a war against Saddam Hussein. But rather than retreat in the face of international doubts, Mr. Bush instead launched a new moral offensive.
Last Friday, after two months of diplomacy, he won a 15-to-0 vote in the Security Council for a UN resolution that could simply catch Iraq in a lie about weapons of mass destruction.
That simple act of noncompliance would be enough, Bush officials say, to trigger a US-led war.
But the problem of persuasive evidence remains. How believable is US intelligence in countering an Iraqi claim that it's innocent? For the rest of the Security Council, the threshold may be high. For a US administration that seems trigger-happy after the tragedy of Sept. 11, just one CIA report of Iraqi deception may be enough to justify firing away.
The chief UN weapons inspector, Hans Blix, told an audience in Moscow last month, "Inspectors may be more likely to encounter smoke than smoking guns. However, smoke might be enough to trigger government concern and action."
Under Resolution 1441, Iraq must reveal by Dec. 8 a list of any plants or materials that could be used for weapons production. That could provide the first tripwire for the US to find Iraq in "material breach" of the UN mandate.
National security adviser Condoleezza Rice says there will be "zero tolerance" of Iraqi lies or obstructions, even, for instance, of a two-hour delay for UN inspectors to gain access to suspected weapons sites.
Iraq lied to the UN often during the 1990s about its weapons, only to be caught but not fully disarmed. Now with a tougher UN resolution giving him a "final opportunity" to disarm, Mr. Hussein may try to hide his weapons programs again or, if his goal is simply to survive, he could give them up and wait a few years to start them again.
But for months, Iraq has claimed it has no such weapons to declare. It will need some incredible excuse if it suddenly finds a "missing" vial of anthrax or a lost missile. Then it is Bush's task to persuade US allies that such a slip-up by Iraq is enough to spark a war.
Europeans, especially, demand irrefutable proof to justify any war. In 1995, after US satellite photos revealed a massacre of thousands of Muslims in Serb-held Bosnia, the NATO members in Europe balked at going to war to bring peace to a corner of their own continent. The US forced them into it. They also looked the other way when genocide broke out in Rwanda in 1994.
Now the UN, led by the US, has set a trap for Hussein in coming weeks to make him come clean. But the world will also be watching the Bush administration to make sure its claims of a "material breach" are clean and credible.
While Hussein has reasons to muddy the waters, the US should not. It has gathered the international community behind it so far. A false tripwire could lose it.