JUST HOURS after polling stations closed in California on November 5th, a Minuteman III missile thundered out of the Vandenberg military base on the Pacific coast. Half an hour later and 4,200 miles away, three mock warheads struck Kwajalein atoll in the Marshall Islands. The timing of the test—announced to both Russia and China—was probably no coincidence: America was sending a message. Whoever was elected, its armed forces were ready to respond to any threat.