How should the United States and its allies deal with regimes that abuse their own people and threaten world order? Are some regimes so evil that it is wrong and unwise to engage with them--even on matters of shared concern? The answer depends not only on the “facts of the case” but also on priorities and frames of reference. Thus, two Soviet citizens, each a Nobel Prize winner, disagreed on whether Western governments should treat the Kremlin as a viable partner in negotiations to control the arms race. . Alexander I. Solzhenitsyn said “yes,” because a regime that oppressed its own people could not be trusted. But Andrei D. Sakharov answered “no,” because the stakes for humanity were so high. Solzhenitsyn put human rights first; Sakharov, the survival of humanity. Today a similar choice confronts Washington, Seoul, and Tokyo as they confront leaders in Pyongyang moving to expand their nuclear and missile capabilities. President George W. Bush placed North Korea on an “axis of evil.” He loathed a leader who permitted more than a million of his subject to starve. But even if this repugnance was justified, did it serve U.S. and allied interests to end the dialogues that, in the Clinton years, offered hope of limiting and perhaps terminating the North’s nuclear weapons and missile programs?“We are good and they are bad” is dangerous as an approach to foreign affairs. But it is also wrong and reckless to assume that all actors are equally flawed. Still, if a cruel dictatorship is willing to negotiate security arrangements likely to limit arms competition and make war less likely, democratic governments should engage and seek verifiable arrangements.