It may not feel like it, but we are closer to nuclear war than at any time since the Cuban missile crisis of 1962. The temptation to dismiss the North Korean dictator Kim Jong-un as a cartoonish figure of fun belies the real and present danger his samurai sword rattling presents. A strange time, then, for Defense Secretary Chuck Hagel to set out on the most thorough reappraisal of our defense spending since the end of Vietnam.