In the midst of the U.S.-South Korean Ulchi-Freedom Guardian joint military exercises, North Korea successfully launched a missile from a submarine stationed on the coast of the East Sea. The Submarine-Launched Ballistic Missile (SLBM) reached 500 km in distance (fired at a high angle) and landed in the sea near Japan. If fired at an ordinary trajectory, the missile is reportedly capable of reaching 1,000 km in distance.

Contrary to previous news coverage of North Korea’s missile tests, the U.S. media appears to be taking the latest missile test more seriously as experts have publicly assessed the SLBM launch as largely successful and a demonstration of “rapid progress.”

The latest missile test has also diminished the case for the U.S.’ deployment of the Terminal High Altitude Area Defense (THAAD) missile defense system in South Korea. Arms control expert Jeffrey Lewis has stated that the submarine launcher is capable of being positioned outside the 120 degree detection range of the THAAD system and fire a long-range missile at a speed faster than that of the THAAD interceptor missile. This means North Korea’s increasing missile capacity could render the THAAD system ineffective against missiles aimed at U.S. bases in the Asia Pacific region.