This time, Iran made the International Atomic Energy Agency's watchdog job easy. Iran did not even make a pretense of complying with the UN Security Council's 30-day deadline to stop enriching uranium and provide more information about its program. The IAEA report issued Friday clearly finds that Iran is noncompliant and, as the Washington Post puts it, "has accelerated, rather than curbed, uranium-enrichment activities." Now the US, France and Britain are drafting another resolution for the UN Security Council that is expected to require Iran to cease uranium enrichment by a certain deadline (perhaps again 30 days), after which Iran would be subject to UN sanctions. At the same time, Russia and China continue to oppose sanctions. Russia seems more concerned about protecting the "right" of Iran - which controls the world's second largest oil reserves - to develop nuclear energy than preventing Teheran from obtaining nuclear weapons. Observing that it was "highly unlikely" that Iran would comply with demands to end enrichment, US Secretary of State Condoleezza Rice rightly said, "The Security Council is going to have a choice. The United States believes, and I think that there are others that believe, that in order to be credible, the Security Council, of course, has to act." Yet at this moment of supposed Western unity, cracks are already appearing. When Rice hinted that a "coalition of the willing" might be necessary to impose sanctions - without even mentioning the possibility of military action - Europeans bristled. Eurodiplomat Javier Solana this week claimed that US and Europe had no differences on Iran. Yet he denied that anyone was seeking a "coalition of the willing" and argued that no European country wanted that. Behind all this delicate diplomatic phrasing threats are flying between the US and Europe. The latter is saying to Washington, "we're with you now, but only so long as you stay where we want you, within the UN Security Council." And the US is saying to its European friends, "we'll take the UN track as far is it goes, but we have to keep other diplomatic and military options open." Obviously, the US would prefer to achieve its objectives multilaterally. The ideal "coalition of the willing" is the UN itself. But what if China or Russia are unwilling? Here, the European bristling seems to imply that, if they are forced to choose between taking action outside the Security Council and allowing Iran to develop a nuclear weapon, they will choose the latter. This stance is doubly counterproductive. First, there is no reason for Iran to back down if that regime believes that the Russian and Chinese vetos will ultimately block serious sanctions, and that Europe will not join the US in acting outside the Security Council. So the European stance directly harms the probability that diplomacy will succeed on precisely the track that Europe is most committed to. Second, as the US has repeatedly pointed out since 9/11, it is those who most believe in using multilateral frameworks who have the most interest in ensuring that those frameworks take effective action and become "credible," as Rice puts it. What does it mean for the international system if it is unable to act against a rogue state that - as Iranian President Mahmoud Ahmadinejad himself said on Friday about the UN demand to end uranium enrichment - "does not give a damn to such resolutions"? Europe is acting as if preventing the US from acting "on its own" is even more important than blocking an Iranian nuke. But Europe, by the lights of its own belief in multilateralism, should have another, no less important objective: proving that the UN system can force a blatant aggressor to back down and thereby remove a dire threat to the international community. It is the US, not Europe, that is now taking the international system seriously and acting in that system's best interest - including when the US threatens to form a "coalition of the willing." Europe should join the US in confronting China and Russia with this stance, which would force those countries to go along or risk shifting the action away from where they enjoy veto power. The best way to bolster the international system is to make it work.