The worst possible outcome of the crisis in the Korean peninsula would be a nuclear war. The second worst would be a conventional one. From these simple platitudes everything else follows. The North Korean regime is undoubtedly vile. Its bombs are unnecessary and bought at the cost of great human suffering. The long-term goal of any foreign policy must be to await and, so far as possible, to hasten the end of the dictatorship. But military intervention is no longer a credible option. It could be argued that it never was. The US military seems to have believed since at least 1995 that any war on the Korean peninsula would result in unacceptable casualties and costs. In that case one of the ironies of the present situation is that North Korea has proved, by building one, that it never actually needed a nuclear deterrent. The threat that its conventional artillery and army posed to the South Korean capital, Seoul, where 10 million people live in their range, was enough to preserve ...