The parallel between Iran and North Korea in their nuclear ambitions is striking. It would be intriguing to know what sort of secret correspondence flows between Tehran and Pyongyang to coordinate political positions in defending their nuclear programs. U.S. intelligence agencies presumably are trying to crack those codes.

Secretary of State Condoleezza Rice sought to connect the two nations in an article in The Washington Post: "Iran is a state sponsor of terrorism that has violated its own commitments and is defying the international community's efforts to contain its nuclear ambitions. North Korea, the least-transparent country in the world, threatens its neighbors and proliferates weapons."

Iran's intransigence came through clearly last week as President Mahmoud Ahmadinejad and Ayatollah Ali Khamenei asserted that Iran would not back down in the face of external pressures. Khamenei was quoted on state television as saying: "The Islamic Republic of Iran considers retreat over the nuclear issue ... as breaking the country's independence."

Responding to a threat of sanctions, Iran's interior minister, Mostafa Pourmohammadi, was quoted by the official Islamic Republic News Agency as saying Iran would use "any means" to resist. Pointing to Iran's oil resources and the Strait of Hormuz, he said: "We have control over the biggest and the most sensitive energy route of the world."

Secretary Rice, in testimony before Congress, indicated that the Bush administration was seeking to undermine the government in Tehran. "We do not have a problem with the Iranian people," she said. "We want the Iranian people to be free. Our problem is with the Iranian regime."

Press reports from Tehran, which looked suspiciously like leaks favoring the administration's stance, reinforced Rice's remarks. The New York Times reported that "cracks are opening both inside and outside the circles of power over the (nuclear) issue." Similarly, the Washington Times said Iranian clerics and business leaders "are increasingly turning against President Mahmoud Ahmadinejad."

Whether regime change will work or, if it did, a more pliable regime would come to office is, at very best, uncertain. If economic sanctions and regime change fail, the Bush administration would be left with a choice between accepting Iran as a nuclear nation and military action to destroy Tehran's capacity for producing nuclear arms. The same would be true for North Korea.

Living with a nuclear-armed Iran would most likely be coupled with a warning that a nuclear attack on the U.S. or U.S. forces or U.S. allies would draw swift retaliation. That warning would be delivered in diplomatic language in public but with forceful language in private. The Pentagon could produce realistic simulations of nuclear destruction to show the Iranians.

Said an experienced strategist who asked not to be named: "Massive retaliation was a credible deterrent throughout the Cold War because successive Soviet leaders were not only rational but conservative. They repeatedly probed soft spots, but backed off when resistance hardened."

He cautioned, however, that "nobody knows whether threats of massive retaliation would deter President Mahmoud Ahmadinejad and his followers who, unlike Soviet leaders, seem to be certifiable nut cases who might welcome irrational risks."

The last resort would be a U.S. assault with conventional weapons to destroy Iran's nuclear facilities, which would be well within U.S. capabilities. Bombers and cruise missiles could wipe out most nuclear reactors, logistics support and electrical systems. Iran's leaders and scientists also would be targets. Nuclear weapons could be used but would not be needed militarily.

The outrage in the Muslim world, if the reaction to political cartoons lampooning the Prophet Muhammad have been any measure, would trigger rampages against American embassies, businesses and citizens everywhere, including possibly within the United States itself. Those eruptions would be accentuated if nuclear arms had been used.

Altogether, no happy prospects here.

Richard Halloran is a Honolulu-based journalist and former New York Times correspondent in Asia.