Last weekend I met a happy hard-liner, a senior White House official, at a Washington party. His good mood, it turns out, had a lot to do with the new, uncompromising stance laid out by his boss, George W. Bush, against Iran. Until recently administration hawks had been somewhat worried about where their president was headed. Since the beginning of his second term, in their view, Bush had gone suspiciously soft on the question of how to stop Iran's nuclear program. He had acceded to Condoleezza Rice's demands that the United States back the multilateral diplomatic approach favored by the Europeans. But in the last two weeks the administration has been on a unilateralist tear against Iran once again, issuing hawkish rhetoric that far outpaces anything heard in European capitals. On Thursday the White House announced a broad array of sanctions that affect almost the entire Iranian government. Tehran, meanwhile, has hardened its own position considerably.

The end result of all this may be war, whether anyone really wants it or not.

On the U.S. side, the uptick in pressure appeared to begin at a news conference on Oct. 17, when the president said, seemingly off the cuff, "If you're interested in avoiding World War III, it seems like you ought to be interested in preventing them [the Iranians] from having the knowledge necessary to make a nuclear weapon." That was a breathtaking statement. What the president seemed to be saying was that World War III would result—and he would be seen as his generation's Neville Chamberlain—if he allowed the Iranians to go beyond the enrichment capability they've already achieved. Bush has no intention of becoming identified with the appeaser of Munich. Bush's jarring statement was followed by an Oct. 21 speech by Vice President Cheney. "We will not allow Iran to have a nuclear weapon," he said flatly. The dynamic duo that brought us the war in Iraq, Bush and Cheney, appear to be on the same page once again. In Tehran, meanwhile, the Iranian government now seems united around one idea: Iran will not give up "one iota" of its nuclear program, in President Mahmoud Ahmadinejad's words. The resignation of chief nuclear negotiator Ali Larijani this week, and his replacement by a close ally of Ahmadinejad's, Saeed Jalili (Larijani and the Iranian president were bitter rivals), is one strong sign that this hardened position will continue. As a Larijani ally in Tehran told me Thursday, the hard-line president likes to dominate "inexperienced and unprofessional people" like Jalili.

Asked whether war has grown more likely, administration officials say no. In the words of Under Secretary of State Nicholas Burns on Thursday, the administration just wants to implement "stronger" diplomacy than it has been able to muster in the U.N. Security Council. "We do not believe conflict is inevitable," Burns said in explaining the new program of unilateral sanctions announced Thursday against Iran's Islamic Revolutionary Guard corps, defense ministry and major banks. "In no way, shape or form does this anticipate the use of force."

But the new U.S. sanctions represent a lurch toward unilateralism that some European officials now fear could be "a repeat of 2002"—in other words, the run-up to the invasion of Iraq. For Washington the ambit of the Iran issue has changed—from a tight focus on Tehran's nuclear enrichment program, in tandem with the Europeans, to a broader indictment of Iran on the world stage. Hence Washington on Thursday named the IRGC, the umbrella organization that many Iranian officials belong to, a proliferator of ballistic missiles, along with the ministry of defense and Armed Forces Logistics agency. And it designated the Quds Force, an elite branch of the IRGC, a group that "provides material support" to the Taliban, Hizbullah, Hamas, Palestinian Islamic Jihad and another Palestinian group. The Bush administration also designated two top Iranian banks—Melli and Mellat—nuclear and missile proliferators, and a third, Saderat, a financier of terrorism. That effectively isolates all three of them as rogues that companies around the world should not do business with if the latter hope to remain part of the international financial system and conduct their affairs in the United States. "The U.S. administration is going ahead on its own," a senior official with one of the "EU3" countries—Britain, France and Germany—said Thursday. "They seem to be putting the question of Iraq in along with [the nuclear issue]," referring to Iranian influence inside Iraq. The Europeans are also resisting painting the Iranian government broadly with the same brush. "We are not going to designate a whole movement [like the IRGC], as opposed to individuals," he said.

So both sides—the United States and Iran—have staked out extreme positions, and it is difficult to see how there can be a negotiated solution. Even if Tehran decides to suspend enrichment, for example—as unlikely as that it is—Washington will still suspect it of proliferation of missiles and support to terrorist groups in Iraq, Afghanistan, Lebanon and the Palestinian territories. No wonder my White House hard-liner was so "relieved," as he told me.