President Bush's 2002 nuclear posture differs sharply from its predecessors and is relevant to the President's recently repeated assertion that he will strike first against any country that might pose a threat of using weapons of mass destruction.

The main new trend in the posture is that the US will be prepared to use nuclear weapons in a much wider range of circumstances than before. Such an emphasis has not been seen since the days of "flexible response" forty or so years ago, when tactical nuclear weapons were deployed in Europe and elsewhere.

Yet, nuclear weapons don't help much with the kinds of missions the US prepares for, including the ones noted in the posture, such as digging out deep underground facilities that might contain bio-warfare agents. Deep underground facilities are difficult or impossible to destroy without large nuclear explosions that create large amounts of fallout. Nuclear weapons are more suited for use against shallow-buried facilities (of the order of ten meters deep) but even in those cases, Hiroshima-type yields are needed, and complete destruction of the bio-agents cannot be guaranteed. Other uses mentioned to justify the posture are even more marginal in their feasibility.

Given the overwhelming US conventional advantage and the relative invulnerability of the US to all but nuclear weapons, the US nuclear posture should aim at minimizing the chances of nuclear weapons spread rather than seeking marginal gains with tactical nuclear weapons. Nuclear weapons are equalizers. Why bring them back into the forefront of regional problems, whether in the Middle East or anywhere else?

Increasing the US nuclear threat will increase the motivation of adversaries, big or small, to improve and extend their own nuclear force, or to get one if they don't already have one. The US cannot subsequently be confident that it will be the only power to use or threaten to use nuclear weapons. There are now several demonstrations of the relative ease with which states can acquire nuclear weapons. North Korea, a poor nation of 17 million people, made and separated with little help enough plutonium for perhaps one or more weapons. South Africa made at least six weapons with essentially no help. Other cases tell the same tale.

The nuclear genie is long out of the bottle and the relative stability that characterized the Cold War is also gone. Instead, the US has been pursuing an aggressive strategy of military expansion around the world and ever closer to other states' vital interests. Quite apart from the wisdom of that strategy, is it wise to couple it with an increased nuclear threat to possible adversaries, as the posture does?

In the past, the existence of a real or putative nuclear threat has been a serious motivation for states to improve and extend their own nuclear force, or to get one if they didn't already have it. That was true of the US, USSR, China, and others. The US, as the world's strongest and least vulnerable major power, should pursue a strategy that minimizes the most serious risk rather than increase it for marginal, and questionable, benefits. The posture implies a strategy that does the opposite.

A nuclear posture better suited to our times would recognize these changes. It would lay the policy basis for the following difficult, long-term, but necessary steps:

1. Minimizing the demand for nuclear weapons, focusing on Asia. Asia contains most of the world's population and might, in a few decades, have most of its wealth. Three states there (four if Israel is included) have nuclear weapons; several more could readily have them. The US nuclear posture should provide US initiatives toward a more stable security order there, one in which peaceful states will not be threatened by nuclear or potentially nuclear rivals. The Non-Proliferation Treaty provides a basis -the only existing basis- for such an order, but it needs to be updated with more inducements in the way of technical cooperation and reassurance, and more clearly defined internationally agreed sanctions if the treaty is disregarded. The US nuclear posture in essence forswears the lead in this endeavor.

2. A pattern for nuclear arms reductions that would include eventually limitations on all arsenals. Openness here is as important as numbers. The US and Russia have most of the weapons but, after the first hundred or so survivable weapons, it matters less and less how many a state has. An internationally recognized framework is needed that can be applied to the regions of the world where nuclear rivalries threaten. Instead, the US has gone the other way, with a sketchy US-Russia agreement that delays the time scale for reductions and does not provide any precedent for international agreements on inspections.

3. A strategy for addressing the problem of nuclear terrorism. The most serious dimension of that problem--the possibility of a terrorist nuclear weapon --is closely related to the proliferation of nuclear weapons and capabilities. Any strategy to avoid that has an important international dimension. Hundreds of tons of weapons-grade uranium and plutonium, most of it surplus in the US and former Soviet Union from the Cold War, need to be better secured and accounted for. A solution to the problem of keeping nuclear weapons and materials out of the tens of millions of shipping containers that crisscross the world requires international cooperation on standards, procedures, cost sharing, and inspections. A good start has been made toward these goals, mainly through the Nunn-Lugar programs, but more money and agreements are needed. A modern nuclear posture should establish the policy basis for securing those resources and agreements. There is at present no comprehensive global strategy for securing such vital agreements and establishing the institutions to enforce them. Consistent, high-priority US participation is vital to secure other countries' participation.

4. A strategy for reducing the risks of accidental nuclear launch while at the same time maintaining invulnerability of the reduced deployments. The nuclear posture briefly mentions the "rigorous safeguards" on US weapons systems and proposes to deal with the problem of accidental or unauthorized launch of "certain foreign forces" via nuclear missile defense. That is at best a partial and certainly a distant remedy. Maintaining the human and financial infrastructure for nuclear weapons system will become more difficult in the US as well as elsewhere. Given the relationship among nuclear deterrent forces, the problem cannot be solved unilaterally. A program that would use US technical leadership to improve warning and control for all states threatened by nuclear weapons is also needed. It is needed now in South Asia. Later, it could help limit crises with or among Russia and China, and help prevent proliferation in the Middle East. President Reagan, with a portion of Star Wars, and, before him, President Eisenhower, with Open Skies, had something of the kind in mind. It is time to begin thinking about how this would look in modern form.

In summary, a nuclear posture for a world with more dispersed power centers and more widely available nuclear technology should have more, not less, emphasis on international agreements. President Eisenhower stated fifty years ago that "Only chaos will result from our abandonment of collective international security." That is even truer in today's world than it was then. The present administration seems to have a bias against such agreements, which are slow to bear fruit and do not win votes. That is shown in the posture itself, which states that arms control measures will not stand in the way of nuclear weapons development.

Yet these and other agreements are essential to deal with the dangers of proliferation to unstable states, with the possible use of international trade for terrorism, and with the risk of accidents and unauthorized launch. Nuclear deterrence continues to be needed, but the last thing a modern posture should do is to bring nuclear weapons back into the forefront of regional deterrence.

Ironically, when it has committed itself to the task, the US has used international agreements more effectively than any other nation. The Cold War-- better called a Cold Peace perhaps, since the military lines of demarcation never changed while the safeguarding of Western values and collapse of the Soviet Union were brought about mainly by economic and political instruments-- saw a rise in US power and influence in good part through the use of US-led international agreements in the areas of trade and security, areas that are necessarily related. Now is not the time to give up that approach, especially not in matters relating to nuclear weapons.

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.

Nuclear weapons states must move to disarm, and nations must join in multilateral approaches to prevent further nuclear proliferation, said Mohamed ElBaradei, head of the International Atomic Energy Agency (IAEA), at CISAC's Drell Lecture on Nov. 4.

"If we are ever to build a global security culture based on human solidarity and shared human values -- a collective security framework that will serve the interests of all countries equally, and make reliance on nuclear weapons obsolete -- the time is now," ElBaradei said. Drawing lessons from Iraq and other recent experiences with IAEA nuclear weapons inspections, ElBaradei called upon politicians, scientists and society to join in international collective actions toward nuclear disarmament.

ElBaradei's lecture was covered by Reuters, the Stanford Daily: U.N. expert cites nuclear danger, the San Jose Mercury News and other news media.