Whoever wins tomorrow is going to want to mend fences with Europe. Sen. John Kerry will want to do this because he believes in diplomacy. President Bush needs European support on challenges such as Iran. The question for either leader will not be whether to make nice with Europe, but rather how to do it. How do you grab a continent that hates you and say, "Wait! I'm not the ogre you mistake me for! We can be friends!"

The answer, whether it's President Bush or President Kerry, is: Propose something so out of character that it forces Europeans to rethink their stereotypes of America. And the best way to do that is to come up with a bold proposal on global warming.

Of all the friction points in the U.S.-European relationship, climate change is the leading candidate for an American about-face. The United States should not appease Europe by abandoning the Iraqis; however misguided the war was, quitting would make things worse. The United States should not appease Europe by signing up to the International Criminal Court; U.S. peacemakers will never go anywhere if they risk being indicted by human rights lawyers. But the United States has every reason to appease Europe on climate change, because on this issue the Europeans are right.

They were not always right, of course. For years the Europeans resisted U.S. proposals for emissions trading, which reduces the cost of cutting carbon dioxide emissions to any given level. At the end of 2000, European blindness on this issue made it impossible for the Clinton administration to sign on to a deal implementing the Kyoto Protocol.

But since 2001 the Europeans have embraced emissions trading, and the broad principles of their climate policy are now sound. First, every rich country should play its part to retard climate change, but it can do that either by cutting its own emissions or by paying other countries to make extra cuts in theirs. Second, poor countries such as China and India should not be expected to do as much, because it isn't their fault that the rich world's consumers have been spewing carbon heedlessly for the past generation or so.

Meanwhile, the Bush administration's position is anything but sound. Bush started out promising to act on climate change. Then, after he got elected, he pretended that carbon emissions weren't a real problem. Then he changed his mind again, but he still refused to take significant action. The respected Pew Center on Global Climate Change recently convened discussions on the next generation of global-warming strategies. Most major governments are participating; oil and coal and car companies are participating; and U.S. Senate staff members are participating. But Bush's officials have declined to show up.

This do-nothing posture confirms every European stereotype of America as a unilateralist rogue that puts the oil industry ahead of policy and ideology ahead of science. But it also isolates the Bush administration domestically. Republican governors in New York, California and Massachusetts have pushed state-level climate-control measures, but the Bush team just growls at them; it is seeking to overturn auto-efficiency standards backed by California's gubernator in court. Equally, the administration is hostile to the reasonable climate-change bill sponsored by Sens. John McCain and Joe Lieberman, which attracted 43 votes last year. The White House is even at loggerheads with some industry leaders, who would prefer the clarity of a climate-control framework to today's policy limbo.

If Kerry gets elected and pursues a more enlightened policy, he will encourage European hopes that America is a rogue no longer and will guarantee a useful honeymoon. But if Bush gets reelected, the case for new thinking on climate change will be still stronger, since he will have a greater need to do something dramatic to relaunch relations with Europe. Despite his oil links, Bush may be flexible enough to grasp that. When he came to office four years ago, nobody imagined that he would announce a big expansion in foreign assistance or a global HIV-AIDS program.

This does not mean that the next president should just sign up to the Kyoto Protocol. So much time has been wasted since its emissions targets were negotiated that they are now unattainable. But the United States does need to embrace Kyoto's cap-and-trade concept and lead the world toward a successor treaty. There is nothing to be gained from clinging to a policy that alienates allies, ignores climatic reality and wastes an opportunity to reduce reliance on unstable Middle Eastern oil.

The fact that this point needs to be argued is itself depressing, for it was not always so. As Vijay Vaitheeswaran writes in "Power to the People," his fine book on energy policy, the United States confronted a challenge akin to climate change two decades ago: the hole in the ozone layer. Then, as now, there were debates on the quality of scientific evidence and the affordability of action and how to broker a multilateral response. But the United States helped to negotiate the Montreal Protocol and Ronald Reagan signed it, and the result is that the ozone layer has been protected from further destruction. If Reagan could do that, surely it's not too much to ask of the next U.S. president. Even -- no, especially -- if the next president is George Bush.