Having to cope simultaneously with the nuclear ambitions of Iraq and North Korea is a heavy burden on the time and attention of the president and his advisers. Yet a double crisis of this kind does have one benefit: It can sharpen our thinking about what is at stake and how to respond.

Until Kim Jong Il entered the picture, many American experts who oppose military action against Iraq argued that keeping Saddam Hussein from getting nuclear weapons was not enough to justify war. Their reason: He might get a few nukes, but he wouldn't use them. Deterrence would keep the nuclear peace, just as it always has.

It's telling that no one has tried to calm the crisis created by North Korea's recent actions by urging us to put our trust in deterrence. (Well, almost no one: Colin Powell said a few more North Korean weapons might be no big deal, but the suggestion was not well received.) With North Korean nuclear weapons becoming a reality, there's a reason our debate doesn't revolve around whether they would be used: Their existence itself has a huge impact. It has produced new North Korean demands for security guarantees, a rupture in the U.S. alliance with South Korea unlike anything we have seen in decades, and renewed talk about whether Japan needs its own nuclear forces.

This is just the start. In time Pyongyang's demands will surely turn to American troop withdrawals from South Korea. And let's not forget the unnerving question of what happens to Kim's stash of weapons when his bizarre regime crumbles or is overthrown.

As the North Korean case suggests, nuclear weapons in the hands of those who are implacably hostile to the United States can severely damage our interests even if they are not used. This may be truer still in Iraq than in Northeast Asia. Because the Persian Gulf region is less stable, its regimes more at odds with one another, terrorist groups far stronger and American ties to friendly states already troubled, the political consequences of a nuclear arsenal under Hussein's control could be very great indeed. (Certainly the effort to keep Iran from becoming a nuclear power would collapse, and when Iran and Iraq face each other with nuclear weapons, even ardent believers in deterrence may lose confidence. In a showdown between them, we'll learn that the United States is not the only country that considers preempting in a crisis.) Does our record in dealing with Iraq also have lessons that apply to North Korea?

A U.S. administration that is counting on multilateral diplomacy and pressures to reverse North Korea's march toward nuclear weapons won't forget the long history of efforts to keep them out of Hussein's hands. Hussein forced international inspectors out of Iraq more than four years ago, and now that Pyongyang has done much the same thing, what we're seeing -- and hearing -- looks very familiar.

Back then, other governments lectured the United States about how Hussein couldn't meet his obligations without concessions in return, about the need to ease both inspections and sanctions, about the futility of force, about how their own economic stakes in Iraq had to be respected, and so on. When long negotiations produced a new inspection system, intended to be more to Hussein's liking, he refused even to let the inspectors into the country. Our friends on the U.N. Security Council promised to keep working on it.

Now we hear that U.S. officials think multilateral efforts may be more effective this time around because the Russians and the Chinese have no illusions about the North Koreans, really don't want them to get nuclear weapons, and have lots of usable leverage. Yet the same Russians who can be blistering in private about Kim's regime used to disparage Hussein too. And it wasn't that they wanted Iraq to have nuclear weapons -- they simply didn't want the problem solved either by American pressure or by confronting Hussein themselves. In the end, that meant letting him off the hook. Today other countries involved in dealing with the North Korean crisis say force, economic sanctions and political isolation are ruled out as levers of either first or last resort. If they mean it, the result may be the same.

Keeping dangerous regimes from getting nuclear weapons is now a cause that the United States has made its own. What divides us from most of our partners in dealing with North Korea and Iraq is not just that they favor quiet diplomacy and tactical finesse and we favor loud, bellicose statements. Others usually share the goal of preventing proliferation, but they rarely see it as a problem whose solution depends on them. Their view is that if diplomatic consultations can give all sides at least something of what they want -- tighter-seeming inspections, firmer-sounding commitments, larger economic rewards for compliance -- fine. But if not, the next step is not to make sure that the offending government pays a heavy price for its actions. No, the next step is to learn to live with a second-best result, to accept remission rather than push for a cure.

The Bush administration says it won't settle for remission, and it wants the Russians and Chinese to muscle the North Koreans for a real cure. That's the right goal, but it will require some strange and difficult diplomacy. For when we rely on others to employ leverage that we lack, we end up having to put pressure on them rather than on our adversaries. One reason we failed to keep Hussein in his box in the past was that we weren't prepared to tell the Russians and others that by failing to support us they put their relations with us at risk. With so little other leverage available to us with North Korea, this may be what it takes to make multilateral diplomacy work. Are we ready?

The writer is a senior fellow at the Council on Foreign Relations and a professor of international diplomacy at Columbia University. He was U.S. ambassador at large for the former Soviet Union from 1997 to 2001.