The single most important security problem that the United States faces is securing loose nuclear materials. A terrorist group can pose an existential threat to the global order only by getting hold of such material. We also have an interest in stopping proliferation, particularly by rogue regimes like Iran and North Korea. To achieve both of these core objectives—which would make American safe and the world more secure—we need Russian cooperation. How fulsome is that likely to be if we gratuitously initiate hostilities with Moscow? Dissing dictators might make for a stirring speech, but ordinary Americans will have to live with the complications after the applause dies down.

To reorder the G8 without China would be particularly bizarre. The G8 was created to help coordinate problems of the emerging global economy. Every day these problems multiply—involving trade, pollution, currencies—and are in greater need of coordination. To have a body that attempts to do this but excludes the world's second largest economy is to condemn it to failure and irrelevance. International groups are not cheerleading bodies but exist to help solve pressing global crises. Excluding countries won't make the problems go away.

McCain appears to think that he can magically unite the two main strands in the Republican foreign-policy establishment. But he can't. This is not about personalities but about two philosophically divergent views of international affairs. Put together, they will produce infighting and incoherence. We have seen this movie before. We have watched an American president unable to choose between his ideologically driven vice president and his pragmatic secretary of State—and the result was the catastrophe of George W. Bush's first term. Twenty-five years earlier, we watched another president who believed that he could encompass the entire spectrum of foreign policy. He, too, gave speeches that were drafted by advisers with divergent world views: in that case, Cyrus Vance and Zbigniew Brzezinski. It led to the paralyzing internal battles of the Carter years. Does John McCain want to try this experiment one more time?

© 2008