A nuclear attack on Tokyo would kill tens of thousands. Here's What You Need to Remember: Tokyo could be struck by multiple nuclear weapons, but North Korea has more targets than weapons at this point, and multiple strikes are unlikely. North Korea would also have Japan’s layered ballistic-missile defenses, consisting of SM-3 interceptors on Aegis destroyers backstopped by the Patriot PAC-3 missile system, to contend with. Tokyo has a population of 13.491 million, making it by far the largest city in Japan and home to more than 10 percent of the nation’s population. The greater Tokyo area, home to thirty-seven million, is the largest urban area on the planet. It is also squarely in the crosshairs of North Korea’s nuclear weapons. In the event of nuclear attack, Tokyo could experience enormous destruction the likes of which it hasn’t experienced since World War II.