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.

Earlier this month, the so-called EU Three--Britain, France and Germany-- achieved an important victory for global security, convincing Iran to suspend its uranium enrichment and plutonium reprocessing activities pending further negotiation on its nuclear question. Though Iran claims that it does not desire a nuclear bomb, the West has long been skeptical of the oil-rich state's contention that it seeks a nuclear fuel cycle for energy purposes alone. Europe and the United States (and of course Israel) will sleep better knowing that Tehran is not pursuing enrichment activities, whatever their alleged purpose.

But the EU3 agreement, which fails to discuss consequences for Iran if it breaks the deal, is vulnerable to being undermined not only by Iran but also by the United States; both have already raised eyebrows in the wake of the accord. Iran raced to produce uranium hexafluoride, a gas that can be enriched into bomb fuel, before it began to observe the temporary suspension on Monday. And both President George W. Bush and outgoing Secretary of State Colin Powell have publicly aired their suspicions that Iran will continue its drive for nuclear weapons under cover of the deal.

At the moment, administration hawks are pressing to confront the mullahs at the United Nations Security Council, where economic sanctions could be considered; calls for using force and for regime change are likely to follow.

Military action is inadvisable at this point, because of a dearth of solid intelligence and the secretive, geographically diffuse nature of Iran's nuclear sites. If the issue reaches the Security Council with the United States and Europe continuing along divergent paths, the inevitable deadlock will deal a severe and lasting blow to international security. Therefore, the agreement must be fortified to keep the Iranians honest, the Europeans effectively engaged and the U.S. hawks bridled.

This can be achieved through a U.S.-European accord laying out trigger mechanisms for specified consequences if Iran violates certain benchmarks. For example, if Iran fails to allow inspectors the access accorded by the Nuclear Nonproliferation Treaty's additional protocol--which Iran is provisionally observing pending ratification--or resumes enrichment and centrifuge-building activities, it could face severe economic sanctions, censure by the Security Council (necessitating cooperation from Russia and China), or in the event of hostility, a forceful response.

We don't know yet whether Tehran will play by the rules. The regime has mastered the art of behaving badly and then seeking rewards for getting back into line. To date, the Europeans have played into its hands, offering carrots for compliance without wielding sticks to punish violations.

Therefore, the Bush administration's apparent comfort with a military option can serve as an important deterrent against Iranian cheating, arming the EU3 agreement with teeth that it would not otherwise have. Iran desires economic incentives but does not yet desperately need them; without a credible threat of U.S.-backed sanctions imposed by the international community, the mullahs can simply decide one day that the restrictions have ceased to be worth their while, and break any deal as though it were merely a business contract.

For the United States, accepting the EU3's carrot-based approach (provided the benchmarks are added) will show the world that it still supports negotiated diplomacy and multilateralism, even in cases where military threats loom. Participating in this framework will also send a message to Iran that the United States is not ruling out renewed relations. This would resonate with the largely pro-American Iranian populace, who despise their regime and are seeking inroads to break free of it.

But if the United States instead presents itself as a unilateralist maverick, it will hinder its own interests; the only thing Iranians disdain more than the mullahs is outside meddling with their deeply nationalistic desire for self-determination. The more overtly hostile the United States acts toward Iran, the more the mullahs are able to spin America's posture to alienate Iranians against the "Great Satan."

The way to keep the Iranian regime in check while speeding its demise is to insure the nuclear agreement through benchmarks and triggers, and then give the mullahs exactly what they ask for in terms of increased access to international institutions like the World Trade Organization.

Such carrots can also be Trojan Horses, allowing the forces of democratic reform within Iran to blossom by enabling pro-democracy elements to make global connections. The U.S. and Europe should saddle up those horses together.

We've been down this road before: A crisis threatens global security, and the international community is not coming together to deal with it. Hawks in the U.S. administration see the Europeans as too timid to use force and reliant on diplomacy to a fault, while many Europeans see the United States as trigger-happy and too impatient with negotiated settlements. This lack of cohesion damaged the legitimacy of the American-led war in Iraq and left U.S.-European relations in tatters. A similar disunity jeopardizes current attempts to manage Iran's nuclear aspirations, even though both sides agree that the threat posed by a nuclear Iran is grave and real.

Departing Deputy Secretary of State Richard L. Armitage positively spun the divergent U.S. and European approaches to Iran: "The [diplomatic] incentives of the Europeans," he said, "only work against the backdrop of the United States being strong and firm on this issue. In the vernacular, it's kind of a good cop/bad cop arrangement. If it works, we'll all have been successful." The problem with Armitage's hopeful outlook is that the good cop/bad cop strategy works only if pursued consciously and in coordination, and the U.S. and European approaches do not reflect that yet. In fact, they seem headed in opposite directions.

The good cops--Britain, France and Germany--recently persuaded Iran to suspend all uranium enrichment-related activities until they reach a final accord. If the mullahs cooperate, they will receive numerous economic carrots, including possible membership in the World Trade Organization (the U.S. would have to agree) and improved trade relations.

In October 2003, when the International Atomic Energy Agency was prepared to take its negative report on Iran's nuclear program to the U.N. Security Council, the mullahs cut a similar deal with the Europeans, promising to suspend all enrichment-related activities. But Iran soon grew impatient with the agreement and resumed efforts to produce the gas that feeds uranium enrichment. It similarly rushed to make as much of that gas as possible before the latest accord's deadline, undercutting confidence in the deal on both sides of the Atlantic. In another bad-faith move, Iran announced last week that it wanted to keep operating uranium-enrichment equipment for research purposes, backing off its pledge to freeze all such activities.

Enter the bad cop--the United States. It has pushed to refer the question of Iran's nuclear aspirations to the Security Council. When Secretary of State Colin L. Powell steps down, the hawkish voices in his department will probably intensify and gain influence, especially if the mullahs break the newest deal.

Armitage might be right that the discordant U.S.-European approaches will push the mullahs to hold to the deal. But the U.S. will be uncomfortable with an agreement that does not insist on any means of enforcement or verification, as is the case with the latest accord.

Iran knows that the war in Iraq colors U.S. conduct toward it. The worse Iraq gets, the less Iran worries--and the mullahs don't seem too worried at the moment. But if they break the accord with the Europeans and the Europeans respond timidly and U.S. resources are freed up as a result of an improving situation in Iraq, the U.S. could take on Iran alone--to everyone's detriment. To avoid this risk, the U.S. and Europe need to harmonize their approaches and develop a coordinated strategy for Iran. The best way to accomplish this is to agree in advance on the consequences Iran will face if it violates its commitments. For example, if the mullahs renege on the latest deal, frustrate the monitoring and verification efforts of IAEA inspectors or fail to ratify an addition to the Nuclear Non-Proliferation Treaty that allows for more invasive inspections, the U.S. and Europe should go to the Security Council, impose economic sanctions or, in the worst case, take military action.

Fortunately, diplomatic disunity over Iran does not run as deep as it did over Iraq, where even the nature of the threat was a bone of contention. Both the U.S. and Europe are worried about a nuclear Iran, and they feel strongly about enforcing the rules of nonproliferation. In June 2003, European foreign ministers required only 45 minutes to approve a document that endorsed U.N.-sanctioned use of force as a last resort against proliferators, as well as "political and diplomatic preventative measures."

If the Europeans agree to leave all responses on the table and to act decisively at the first sign of Iranian mischief, the United States would be foolish not to form a partnership with them. (It's also important that the U.S. set a better example as a member of the nonproliferation community by abandoning plans to build new mini-nuclear weapons and ratifying the Comprehensive Test Ban Treaty.)

The role the U.S. forges for itself in dealing with Iran will have significance beyond reinvesting in international order or responding to the mullahs' nuclear ambitions. Iran's despotic regime will collapse some day, and there will be a "morning after" similar to that in Iraq, where reconstruction efforts have floundered because U.S. planners underestimated the challenge of nation-building and the need for international support to make it work. When Iran makes its move toward a better government, the U.S. should be in a position to lead a coherent, collective international effort to help it get off the ground.

Yet since the severing of U.S.-Iranian ties in 1980, the U.S. has been slack in developing a viable Iran policy. Iran's nuclear ambition should be motive enough to reverse this inattention. U.S. policy toward Iran must cease to be reactive, as it is now.

In addition to working with the Europeans to curb the mullahs' nuclear efforts, the U.S. should begin crafting a strategy to work toward--and then with--a democratic Iran. Supporting a government that complies with its international obligations is certainly preferable to containing one that thwarts them. By getting involved now, the U.S. can do much to show Iranians that it will be a friend to a free Iran. A democratic Iran may still want a nuclear bomb as a matter of national pride. But a less threatening, pro-diplomacy U.S. would be in a stronger position to argue the benefits of membership in the nonproliferation community rather than life as a rogue power.

Participating in a multilateral approach to Iran's nuclear program is a great place to start. In doing so, the U.S. will signal to Iranians that its aggressive position does not reflect a desire to remake Iran in its own image but rather a desire to achieve, alongside Europe, a substantial victory for nonproliferation and international security.

Neither the Bush nor the Kerry campaign has chosen to make U.S. policy toward North Korea a central part of its election platform -- and for good reason. Both sides recognize that it may no longer be possible to peacefully resolve the dispute over that country's nuclear-weapons development, and a debate over whether to wage another controversial war would hardly appeal to the electorate.

The fundamental problem is that North Korea believes it needs a sizable nuclear arsenal. Politically, such an asset would transform the country into a regional power whose views on international issues must always be taken seriously. Militarily, the possession of a large number of atomic weapons would bolster North Korea's security by discouraging intimidation of the sort Washington employed in 1994, when it forced President Kim Jong Il to shut down his plutonium-based arms program.

Most compelling, however, is Pyongyang's financial situation. The North Korean economy is so dysfunctional that it cannot reliably generate enough wealth to sustain the state. Kim and his colleagues have dabbled in reform, but they apparently realize that the degree of liberalization necessary to produce strong GDP growth would coincidentally release a wave of popular animosity sufficient to wash the government away. Thus, the safest course of action is to leave the economy unreconstructed while securing a constant stream of foreign aid.

Since Pyongyang needs leverage to obtain this support, it is determined to amass a big nuclear force. The international community would then have no means of persuading North Korea to abandon its weaponry short of risking catastrophic war and would consequently be reduced to bribing the Kim government not to use its new capabilities.

Moreover, if the flow of aid were interrupted, Pyongyang could garner the foreign exchange it requires by selling its new technology, fissile materials or even a few of its bombs.

What this implies is that despite its rhetoric to the contrary, North Korea does not really want to trade its nuclear program for economic assistance and a security guarantee. Pyongyang would plainly prefer to embark on diplomatic talks with nuclear weapons in hand. This is why it cheated on the 1994 agreement by enriching uranium and why it resumed reprocessing plutonium in early 2003. But to realize his strategic aspirations, Kim must still prevent the United States, China, Japan and South Korea from forming a coalition that imposes crippling sanctions before his armament effort has reached fruition.

Driving wedges between the other regional powers is not as difficult as it might seem. Paradoxically, perhaps, the United States is the only relevant country that views the achievement by North Korea of significant nuclear status as absolutely unacceptable.

Tokyo and Seoul are worried about that eventuality but conversely fear the geopolitical instability and refugee crisis that would ensue if economic or military pressure caused the Kim regime to collapse. Beijing shares these immediate concerns and additionally worries about the longer-term possibility that a united Korean Peninsula might incline toward the United States.

Only by alleviating these anxieties can the U.S. government unite East Asia against North Korea.

Washington, however, is constrained by its own internal rift. On the one hand are those doves who want to exchange aid and a security arrangement for the termination of North Korea's nuclear projects, on the other are the hawks who oppose all diplomatic contact with the Kim government. The conflict between these two camps has paralyzed Bush administration policy, leaving Pyongyang more or less free to proceed with its nuclear gambit.

If the doves err in overestimating Pyongyang's flexibility, the hawks are guilty of the more serious mistake of thinking that a refusal to negotiate with mendacious states is an actual diplomatic strategy.

In fact, the talks advocated by the doves are an essential step toward the application of coercive force. It is only by offering reasonable deals, and having the Kim government reject them, that Washington can demonstrate to Beijing, Tokyo and Seoul that Pyongyang cannot be bought off with money and a verbal guarantee of its security. This recognition, in turn, is critical both to building a coalition against North Korea and, alternatively, to reducing the political costs of unilateral U.S. military action.

The better course has therefore always been to negotiate earnestly with Pyongyang in the hope that it would accede to a peace agreement while knowing that its failure to do so would facilitate the adoption of more assertive measures, if necessary, at a later date.

Yet rather than taking every opportunity to interact with Kim's representatives, the Bush administration has limited its diplomacy to desultory exchanges at multilateral conferences and only put forward a detailed settlement proposal in June. Pyongyang has exploited the opening created by this stubbornness fairly effectively. It has capitalized on anti-American sentiment in South Korea by persuading Seoul to cooperate economically and militarily while also prevailing upon Tokyo to resume large-scale food aid and seek an early exchange of ambassadors.

In the occasional six-party talks with delegations from China, Japan, Russia, South Korea and the United States, Pyongyang's objective has been to stall for time. Its diplomats have postponed specific meetings many times; then behaved so egregiously that the other participants were relieved when the North Koreans consented merely to engage in future negotiations. Those too, however, would soon be rescheduled.

Washington has inadvertently abetted these tactics through thoughtless insults -- canceling, for instance, informal exchanges between U.S. and North Korean officials at the last minute -- which Pyongyang could then cite as proof that the United States was not acting in good faith.

North Korea has also benefited from the awkward developments that inevitably arise when sensitive dialogues are delayed. Seoul's recent declaration that it had reprocessed a small volume of nuclear material is one such event; Pyongyang may use that admission to complicate the next round of six-party discussions. Thus the Kim government buys more time for its nuclear technicians to continue their work.

It is true that North Korea has committed some blunders over the past two years, but it has played its cards more adroitly than the United States. The members of a potential coalition are largely going their own way now, and the odds that those countries will unite behind any U.S. strategy, peaceful or otherwise, have diminished considerably.

So, unless the winner of the November election acts quickly and with better judgment than Washington has so far, the United States may soon be forced to choose between launching military strikes without foreign support and letting Kim attain the nuclear status he desires.

ROBERT MADSEN is a fellow at the Asia-Pacific Research Center, Stanford Institute for International Studies. He wrote this article for Perspective.