Iran claims that it can produce enough weapons-grade uranium for a nuclear weapon within a year. According to Undersecretary of State John Bolton, "We cannot let Iran, a leading sponsor of terrorism, acquire nuclear weapons." Bolton claims that the "regime has to be isolated in its bad behavior" (although if North Korea is any example, such action will simply accelerate Iran's quest for nuclear weapons). Bolton also wants "concerted, immediate intervention by the international community."

But since so many of the assumptions about the threat posed by Iraq have been so wrong, the United States needs to avoid the same mistake of rushing to judgment about Iran.

It's easy to paint a picture of Iran as a threat to America. After all, it's a country ruled by Islamic fundamentalist clerics who are hostile to the United States. And because al-Qaida's radical Islamist ideology is also fundamentalist, many people don't see any difference between the two. Finally, most Americans haven't forgotten the 52 Americans taken hostage after the U.S. Embassy in Tehran was seized in November 1979. So Iran is considered a long-standing nemesis. That doesn't automatically make it a grave threat.

Iran claims its nuclear program is for peaceful purposes. The United States assumes otherwise based on the discovery in December 2002 of two secret nuclear-fuel-cycle facilities at Natanz and Arak. Previously, Iran's nuclear program was thought to be confined to the light-water reactor facility in Bushehr.

Subsequently, the International Atomic Energy Agency found traces of highly enriched uranium, deemed questionable for non-military purposes, and blueprints and parts for P2 centrifuges suitable for producing weapons-grade plutonium. Iran has since announced that it was going to resume centrifuge activities, which are allowed for peaceful nuclear energy but not for making weapons.

Although Iran's claims about being able to build a nuclear weapon within a year could be boasting, it's clear that Iran's nuclear program is more advanced than Iraq's was. But even if Iran is able to build a few weapons in the near future, the mullahs in Tehran can no more ignore the reality of deterrence and the vast U.S. strategic nuclear arsenal than could the Soviet Union before or North Korea now.

To be sure, a nuclear-armed Iran would not be a welcome situation. But it may well be a situation that the United States must find a way to live with or else face the prospect of war. Indeed, if one accepts the logic of pre-emptive action, the United States would have to wage war against the 12 nations with nuclear weapons programs that the Pentagon says are extant and emerging threats.

A legitimate concern about Iran's nuclear aspirations is that country's ties to terrorism because, by definition, terrorists are not deterrable. According to the State Department, "Iran remained the most active state sponsor of terrorism in 2003." It's no secret that Iran provides funding, safe haven, training and weapons to anti-Israeli groups such as Hezbollah and Hamas. But, like Iraq, Iran has not supplied terrorist groups with chemical or biological weapons to use against Israel. So it's not clear what incentive Iran would have to give nuclear weapons to terrorists. Indeed, Israel's nuclear arsenal (believed to be as many as 200 warheads) serves as a powerful deterrent against Iran taking such action.

Iran's terrorist ties were also cited by the 9/11 Commission, which implicated Iran in the 1996 Khobar Towers bombing and cited "strong evidence" that Iran facilitated the transit of several al-Qaida members before 9/11 (including perhaps eight or more of the hijackers). The commission did not say, however, that Iran was involved with the attacks. President Bush responded to the possibility of an Iran-al-Qaida connection with rhetoric that sounded like an instant replay of accusations made against Iraq in the run-up to that war - claiming Iran was harboring al-Qaida leadership, had a nuclear weapons program that must be dismantled and needed to stop supporting terrorist groups.

The potential Iran-al-Qaida connection is a serious issue that deserves further investigation. But without clear evidence that the regime in Tehran was involved in 9/11 or is otherwise supporting or harboring al-Qaida, the United States cannot afford to wage another unnecessary war as it did against Iraq.

Even if the idea of a war against Iran seems unlikely or absurd (especially with 140,000 U.S. troops tied down in Iraq), some hawks advocate the so-called Osirak option (referring to Israel's pre-emptive strike on Iraq's nuclear reactor in 1981) against Iran. (Indeed, it's entirely possible that the Israelis might choose to do the same thing again.)

But whether it's a U.S. or Israeli operation, the risk is how good the intelligence is on the location of Iran's nuclear facilities. After all, the United States was surprised to discover that Iran's nuclear activities were not limited to Bushehr, so are there other unknown sites? Even a limited strike with precision weapons against Iran could be a dangerous roll of the dice.

Ultimately, the United States is left with having to choose from a menu of less than savory options in response to Iran's nuclear weapons program.

Efforts to convince the Iranians to give up their quest for nuclear weapons should not be abandoned, but success in that long-shot strategy cannot be the only acceptable outcome.

Other options must be explored, such as how to limit the size and scope of Iran's nuclear weapons program and arsenal so that it is not a direct threat to the United States, and ensuring that weapons, materials and technology are not transferred to terrorists.

But that's not likely to happen if the U.S. policy towards Iran is to isolate it. For now, that leaves engagement as the most prudent course of action that could yield a productive outcome.