Even when the European-Iranian agreement to halt Iran's uranium-enrichment program looked solid, the United States was blunt in its disapproval. The ink was barely dry on the accord when the Bush administration, it appears, began trying to derail it.

First, rather than endorse the accord, Secretary of State Colin Powell essentially accused the Iranians of lying when they said their nuclear program was for peaceful purposes. He announced that new intelligence showed Iran is developing a nuclear warhead to arm its Shahab-3 ballistic missiles. Then, at a Nov. 20 meeting of heads of state in Santiago, Chile, President Bush stated unequivocally that Iran is trying to build a nuclear weapon.

Why would the administration take such a combative stance? Because hard-liners within the administration thought Tehran would use the settlement to buy time for building nuclear weapons, and that the United States would be better off bombing Iran's suspected weapons sites.

Proponents of using military force against Iran have not yet won the argument within the Bush administration. But the past two weeks of strong pronouncements about the threat Iran poses suggest that the military option may be gaining ground. And Iran's last-minute attempts to maintain some enrichment capabilities -- which by press time Friday were threatening to kill the European agreement -- no doubt strengthened the hard-liners' hand.

Before the United States even considers such a drastic step as airstrikes against suspected nuclear weapons sites -- or even trying to compel the United Nations to endorse new economic sanctions against Iran -- it is essential that our leaders be clear about what they are trying to accomplish in Iran and whether such actions will help or hurt.

If the ultimate goal is to create a democracy -- one that would not fear the United States and therefore have less use for the bomb -- then dual-track diplomacy with Iran's government and with its people is more likely to work than military action.

Probably the most important question the administration's leaders should ask themselves is whether Iran, even a nuclear-armed Iran, poses a direct threat to the United States and its allies.

The answer, we believe, is no.

The mullahs who rule Tehran long ago gave up their ideological quest to "export'' revolution. Like the last generation of octogenarians who ruled the Soviet Union, Iran's leaders today want nuclear weapons as a means to help them preserve their power, not to help them spread their model of theocratic rule to other countries.

Deterrence works

In other words, even if Iran's rulers succeeded in building nuclear bombs, they would be very unlikely to take on the United States and its vast nuclear arsenal or to attack Israel. (The mullahs in Tehran understand that any nuclear attack against Israel would trigger full retaliation from the United States.) In dealing with Iran, deterrence works.

Tehran would also be unlikely to pass a bomb to Islamist terrorists, despite its support of Arab terrorist organizations that continue to attack Israel. One reason, again, is deterrence. Iran's rulers know that the United States would probably be able to trace the weapon back to them and retaliate.

The threat of a nuclear Iran comes, instead, from the reaction it is almost sure to spark in the region and the world, possibly sending Egypt and Saudi Arabia on their own quests for nuclear weapons.

Such an arms race would undermine the longstanding Treaty on the Non-Proliferation of Nuclear Weapons, an agreement signed by nearly 190 countries, that has proved indispensable in preventing the spread of nuclear weapons.

Bush administration hard-liners want to save that arms-control treaty by using arms. In advocating a "surgical'' military strike against Iran's most important nuclear facilities, including the once hidden enrichment plant in Natanz, they cite Israel's airstrike against Iraq's nuclear complex at Osirak in 1981 as a model of success. They argue that an American (or Israeli) strike would not end Iran's nuclear aspirations, but would dramatically slow its program and make the mullahs reconsider the costs of trying to restart it.

Attack would backfire

But a pre-emptive military strike would instead do just what the hard-liners in Tehran hope for: It would unite their people behind them.

Even a precise bombing campaign would kill hundreds if not thousands of innocent Iranians; destroy ancient buildings of historical and religious importance; trigger an Iranian counterstrike, however feeble, against American targets and friends in the region, and spur the mullahs to increase their direct support for American enemies in the Shiite part of Iraq.

Even more important, an attack would only encourage Tehran to redouble its efforts to build a bomb, just as Saddam Hussein sped up his efforts after the 1981 strike. It would also hurt the democratic opposition movement inside Iran, which is already in retreat and cannot afford another setback. After an attack, Iranians, not unlike Americans, are sure to rally around the flag and their government.

If the administration decides, in the end, that American military options are limited and counterproductive, the only serious way to impede the development of Iranian nuclear weapons is through negotiation. Iran's recent accord with France, Britain and Germany is only temporary, and negotiations are expected to continue.

If the United States were to jump in now, it could try to ensure that our European allies accept nothing less than a permanent and verifiable dismantling of Iran's enrichment capabilities, as well as banning any plutonium production.

Allowing the Iranians to enrich even some uranium, which they say will be used merely to feed their nuclear power plant, makes it too easy to cheat. To make the deal work, the United States would need to join with Europe, Russia and China in pledging to guarantee Iran a permanent and continuous supply of enriched uranium. To make the deal even more attractive, the fuel could be offered at reduced prices.

Even under the strictest inspection regime, Iran's leaders will cheat, as they have often done in the past, and they will eventually divert enriched uranium from peaceful to military purposes. But the harder and more transparent the allies can make it, the longer it will take Iran to begin building bombs.

In the long run, the world's only serious hope for stopping Iran from developing nuclear weapons is the development of a democratic government in Tehran. A democratic Iran will become an ally of the Western world no longer in need of a deterrent threat against the United States.

Democracy in Iran therefore obviously serves U.S. national interests. Yet Bush administration officials (as well as their predecessors in the Clinton, Bush and Reagan administrations) have not succeeded in developing a strategy for advancing the cause of Iranian democracy.

New strategy

What is needed is a radical new approach that would nurture change from within the country, in alliance with Iran's democratic movement, rather than impose change from without.

A first step would be to establish an American presence in Tehran, as many in Iran's democratic opposition have proposed. Now decades old, the U.S. policy of isolating Iran has not weakened but instead strengthened its autocratic government.

Of course, we are not suggesting that the United States open an embassy in Tehran and turn a blind eye to human rights abuses; that would only contribute to the further consolidation of the mullahs' hold on power. But we are suggesting a new strategy that would allow American government officials, as well as civic leaders, academics and business people, to engage directly with Iranian society.

This engagement cannot occur on a widespread scale without some level of diplomatic relations and some revision of the American sanctions against Iran. Then, more Western foundations would be able to make grants to pro-democracy Iranian organizations, while business people -- and especially the Iranian-American business community in the United States -- would be able to leverage their capital and know-how to influence economic and political change inside Iran. A U.S. presence in Iran would, not incidentally, also enhance the West's ability to monitor Iran's nuclear program.

Critics of engagement argue that diplomatic relations with Iran will reward this "axis of evil'' member for years of supporting terrorism and pursuing nuclear weapons. In fact, an American presence in Iran is the mullahs' worst nightmare.

Iran's government has long used its ongoing tensions with the United States, as well as the embargo, as an excuse for the economic difficulties that are, in fact, the direct results of the regime's incompetence and corruption. Tehran's leaders have conveniently labeled nearly all of their opponents as "agents of America.''

Most important, part of the regime's self-declared legitimacy lies in its claim to be the only Muslim country fighting what it sees as U.S. imperialism. If the United States could prove it's not an enemy of the Iranian people, the legitimacy of Iran's leaders would diminish.

Reagan's course

In the first years of his presidency, Ronald Reagan labeled the Soviet Union the "evil empire'' and went out of his way to avoid contact with such a regime.

Over time, however, Reagan charted a new course of dual-track diplomacy. He engaged Kremlin leaders (well before Gorbachev) in arms control, while also fostering contacts and information flow between the West and the Soviet people in the hope of opening them up to the possibilities of democracy.

In the long run, it was not arms control with the Soviets, but democratization within the Soviet Union, that made the United States safer.

If George W. Bush desires a foreign-policy legacy as grand as Reagan's, now is the time to think big and change course as dramatically as Reagan did.