North Korea on Tuesday conducted its 11th missile test of the year. Pyongyang claimed — and the U.S. government confirmed — that it was an intercontinental ballistic missile. The Hwasong-14 missile reached an altitude of 2,100 km and flew more than 930 km to land in the waters of Japan's exclusive economic zone. North Korean media hailed the "shining success" and experts believe that it demonstrates that country's ability to hit the United States, a long-cherished goal of Pyongyang. As a North Korean government spokesperson declared after the test, Pyongyang "will fundamentally terminate the U.S. nuclear war threats and blackmail, and credibly protect the peace and stability of the Korean Peninsula and the region."

Contrary to that assertion, a successful ICBM test does not mean that Pyongyang can deliver a nuclear warhead to U.S. territory, although North Korea is inching toward that objective. More worrisome is the North Korean belief that it has that capability and that it can deter the U.S. from taking action to stop Pyongyang from threatening neighbors and ignoring international law. Washington remained committed to the defense of its allies throughout the Cold War when the Soviet Union threatened retaliation against the U.S. homeland with many more nuclear weapons than the North will ever muster.

North Korea must be stripped of the illusion that the U.S. can be decoupled from Japan and South Korea, its two Northeast Asian allies. Close coordination between Washington, Tokyo and Seoul is critical to the realization of that goal. Pyongyang's dream is to divide our three nations; we must work harder to ensure that North Korea does not miscalculate or exaggerate its capabilities.