North Korea has once again signaled its determination to flout international rules and world opinion, and take actions that risk regional peace and stability. The test of an intermediate-range missile this past weekend has pushed the challenge of dealing with the regime in Pyongyang to the top of the security agenda. Plainly, a policy shift is in order as North Korea continues its nuclear and missile modernization programs without interruptions. Unfortunately, there are as yet no good solutions to this problem.

North Korea on Sunday tested what is believed to have been a modified intermediate-range missile. It traveled 500 km from its launch site at Banghyon air base in the western part of the country and splashed down in the Sea of Japan. The test was the first of the year by the North, and was not an intercontinental ballistic missile as many had feared. In his New Year address, supreme leader Kim Jong Un said that his government was in the "final stages" of developing an ICBM. North Korea has never successfully tested such a weapon. When that does happen, a missile that can deliver a nuclear warhead thousands of kilometers away — in other words, capable of reaching the continental United States — will be, for U.S. defense planners, a "strategic game changer."

The immediate question after every North Korean test is, why now? Some in South Korea believe that the test was intended to mark the birthday of Kim Jong Il, Kim Jong Un's father. But the test also followed the phone call between U.S. President Donald Trump and Chinese President Xi Jinping, a conversation that restored some stability to that bilateral relationship after Trump questioned the "one-China" policy that Beijing insists is the foundation of its relations with any country. Trump has indicated that he believes China is the key to getting North Korea to end its provocative behavior; according to this logic, the test is Pyongyang's way of demonstrating the limits of Chinese influence.