North Korea successfully tests submarine-launched missile

North Korea on Wednesday fired a submarine-launched ballistic missile that flew 310 miles, a range that puts all of South Korea and parts of Japan within striking distance.

The North has been aggressively pursuing the development of miniaturized nuclear warheads designed to be launched by land-based ballistic missiles capable of reaching South Korea and Japan. But a submarine launch is more difficult to detect and intercept with anti-ballistic missile systems such as the Theater High Altitude Area Defense (THAAD) system planned for deployment in South Korea.

“North Korea’s nuclear and missile threats are not imaginary threats any longer, but they’re now becoming real threats,” South Korean President Park Geun-hye said of the launch. “Those threats are coming closer each moment.”

Previous North Korean submarine launch tests have ended in failure, with the missiles exploding in midair after flying no more than 18 miles, according to South Korean defense officials. But the 310-mile range achieved during Wednesday’s launch may not demonstrate the missile’s full range, since it was fired at a very steep angle, according to South Korea’s Yonhap News Agency. If launched at a lower angle, analysts estimate the missile could have flown more than 600 miles.

“We don’t know the full range, but 500 km (310 miles) is either full range or a full range on a lofted trajectory. Either way, that missile works,” Jeffrey Lewis of the California-based Middlebury Institute of International Studies told Reuters.

The submarine test launch took place just two days after the U.S. and South Korean militaries began their annual joint exercise, Ulchi Freedom Guardian. North Korea has frequently threatened retaliation over these exercises, which it deems a rehearsal for invasion.

The launch also occurred as tensions between the two Koreas have ratcheted up following the defection of a senior North Korean diplomat in London, as well as U.S. plans to deploy the THAAD missile defense system in South Korea.

China, historically a North Korean ally, opposes the North’s nuclear and missile programs as well as any provocation that could raise tension levels on the Korean Peninsula, according to a Reuters report of a statement made Wednesday by Chinese Foreign Minister Wang Yi.

While military provocation may be the most visible aspect of North Korea’s breakthrough in submarine-launched missile technology—a capability achieved by only six other countries—some analysts think the launch was designed more for national prestige.

“I think it’s meant foremost as a demonstration of sheer technical capability and a demand for status and respect,” Joshua Pollack, editor of the U.S.-based Nonproliferation Review, told Reuters.