Earlier this month, North Korea launched four ballistic missiles toward Japan. Three of them landed within Japan’s exclusive economic zone, less than 200 miles from the country’s coast, in an area frequented by Japanese fishing boats. The missile test, North Korean state media claimed, was aimed at “the bases of the U.S. imperialist aggressor forces in Japan.” By demonstrating that it could carry out a so-called saturation attack—one in which a massive barrage of missiles would overwhelm Japan’s defenses—Pyongyang sought to weaken the credibility of the military deterrent that Japan, the United States, and South Korea have erected against it.
North Korea has conducted dozens of missile tests and three nuclear tests since Kim Jong Un took office in late 2011. Over the same period, Pyongyang’s missile capabilities have grown and its arsenal’s vulnerability to attack has diminished.
Last August, North Korea successfully tested a submarine-launched ballistic missile. In February, it tested an intermediate-range ballistic missile propelled by solid fuel—a technological leap that would allow Pyongyang to dramatically reduce the signs of an impending launch, helping to insulate its missiles from preemptive strikes. The Kim regime is now attempting to create a nuclear warhead small enough to attach to the tip of a missile, a step toward its ultimate goal of creating an intercontinental ballistic missile that could deliver a nuclear bomb to the continental United States. Through an elaborate shell game involving mobile missile launchers and the diversification of its launch sites, North Korea has sought to sow doubts in the United States, Japan, and South Korea about the potential efficacy of preemptive action.
All of these developments have worried Japanese policymakers, deepening a long-standing debate in Tokyo over the country’s security posture. At issue is whether enhancing Japan’s missile defense capabilities will be enough to meet the threat and whether Tokyo should equip itself for a preemptive strike against North Korea—a move that could raise China’s ire and