We have spent months debating Barack Obama's suggestion that he might, under some circumstances, meet with Iranians and Venezuelans. It is a sign of what is wrong with the foreign-policy debate that this idea is treated as a revolution in U.S. policy while McCain's proposal has barely registered. What McCain has announced is momentous—that the United States should adopt a policy of active exclusion and hostility toward two major global powers. It would reverse a decades-old bipartisan American policy of integrating these two countries into the global order, a policy that began under Richard Nixon (with Beijing) and continued under Ronald Reagan (with Moscow). It is a policy that would alienate many countries in Europe and Asia who would see it as an attempt by Washington to begin a new cold war.