According to the latest news out of the Korean peninsula, North Korea has moved to its east coast two intermediate-range ballistic missiles on mobile launchers. While the missile type has not been confirmed, many reports identify it as a Musudan, which they describe as untested. That may not be quite true. According to North Korea expert Bruce Bechtol, as he described in his book Defiant Failed State, Pyongyang has exported the Musudan to Iran, which renamed it the Shahab-4 and successfully tested in 2006:
The North Koreans reportedly sold eighteen of these systems to Iran in the fall of 2005. The Iranians did not wait long to test this missile (named Shahab-4) and conducted their first test launch on January 17, 2006. The missile flew a full three thousand kilometers, and the Iranians intentionally destroyed it in mid-flight. Performance data recovered from the test flight revealed a range capability of four thousand kilometers for the missile. North Koreans were likely present at the launch.
The Musudan, then, may be effective, and presents a threat to U.S. allies and territories in Asia. Just why Kim Jong-un has positioned two of these missiles on his eastern seaboard is unclear, but April 15, the birth North Korean founder Kim Il-Sung, would provide an occasion for the young Kim to carry out another test launch. If he does so, the United States, South Korea, and Japan must intercept and destroy the missile in flight.
Over the past few weeks, North Korea has been explicitly threatening the United States and her allies with nuclear attack. While nobody expects Pyongyang would carry out that threat—even if it was capable of doing so, which it is likely not—we simply know too little about Kim the man and about the current internal dynamics of his regime to warrant too much confidence in predicting the North’s behavior.
Unless North Korea launches towards China or Russia, which it won’t, a launch in virtually any direction will potentially endanger the United States or its allies. To allow a launch to proceed unimpeded following numerous North Korean threats of missile strikes would convey a striking lack of seriousness in America’s approach to its own defense and that of its allies.
The United States and its Asian allies have been wisely moving missile defense assets into place to ensure they can defend against a North Korean missile launch. Failure to put those assets to use in the event of such a launch—even if determined to be a test—would only serve to embolden Kim, making him more confident that he can dangerously escalate tensions without repercussion.