Why America's Missile Defenses Might Not Work Against North Korea

by Dave Majumdar, The National Interest, September 17, 2017

Late last week, the United States tracked a North Korean intermediate range ballistic missile (IRBM) test that once again overflew Japan before landing in the Pacific.

The IRBM is the latest in a series of North Korean provocations this year that has included the test of a hydrogen bomb and an intercontinental ballistic missile (ICBM) among other events. There is little the United States and its allies can do in response except to deter Pyongyang. Suggestions that the United States and Japan shoot down North Korean missile tests—an option often bandied about by certain political commentators are fanciful. Neither the United States or Japan likely has such a capability—even if they were so inclined.

“U.S. Pacific Command detected and tracked what we assess was a single North Korean ballistic missile launch at 11:57 a.m. (Hawaii time) Sept. 14. Initial assessment indicates the launch of an intermediate range ballistic missile (IRBM),” U.S. Pacific Command spokesman Cmdr. Dave Benham wrote in a Sept. 14 email.

“The launch occurred in the vicinity of Sunan, North Korea and flew east. The ballistic missile overflew the territory of northern Japan before landing in the Pacific Ocean east of Japan. We are working with our interagency partners on a more detailed assessment and we will provide a public update if warranted.”

Kingston Reif, director for disarmament and threat reduction policy at the Arms Control Association told The National Interest last month that intercepting such tests would be extremely difficult. Other experts also agreed with Reif’s assessment.

“Shooting down a North Korean missile on a test trajectory—as was the case with the 8/29 HS-12 test—is an entirely different and even more difficult challenge,” Reif said.

“Our BMD systems are not designed or postured to defend the open ocean. And we couldn't rely on THAAD, since there are no THAAD batteries in the Japan. Patriot is also a no go, since it is designed to defend against slower short-range missiles during their terminal phase.”

In theory, it might be possible to shoot down North Korean ballistic missiles below the intercontinental ballistic missile (ICBM) class using the U.S. Navy’s Aegis cruisers and destroyers. However, it would be extremely difficult—and would compromise the defenses of populated areas.

“Shooting down a North Korean non-ICBM test might theoretically be possible using SM-3 interceptors launched from Aegis ships in the region,” Reif said.

“But it would be a highly demanding task and entail a significant amount of guesswork, as the ships would have to be in the right place at the right time to stop a test at sea. Doing so also would mean taking them away from optimal positions to defend actual targets on land.”

read … The National Interest