North Korean Submarine Missile Launch Could Complicate BMD Strategy
The successful launch by North Korea of a submarine-launched ballistic missile (SLBM) is a significant achievement and, if deployed, could complicate U.S. and allied efforts to provide an umbrella of ballistic-missile defense (BMD) in the Northwestern Pacific.
“U.S. Strategic Command systems detected and tracked what we assess was a North Korean submarine missile launch at 3:29 p.m. CDT, August 23, 2016,” said an Aug. 23 U.S. Pacific Command statement. “The launch of a presumed KN-11 submarine-launched ballistic missile occurred off the coast of Sinpo. The missile was tracked over and into the Sea of Japan, approximately 300 miles off the coast of North Korea. The North American Aerospace Defense Command determined the missile launch from North Korea did not pose a threat to North America.”
North Korea’s ballistic-missile and nuclear weapons programs have long been a concern of the United States and allied nations in the Pacific region, and even pose a potential future threat to the continental United States. If its SLBM capability is developed and deployed, North Korea would join an exclusive club comprising the United States, United Kingdom, France, Russia and China.
The missile probably was launched from an ex-Russian modified Golf II-class ballistic-missile diesel-electric submarine (SSB). The Golf-class SSBs were first built in 1958 by the Soviet Union. The initial variant, the Golf I, could launch three SS-N-4 nuclear warhead-tipped missiles, but it had to surface to do so. The Golf II variant had the capability of launching three SS-N-5 missiles while submerged.
By the 1980s, the Golf class SSBs had been superseded on SLBM patrols by their nuclear-powered successors in the Atlantic and Pacific, but were believed by Western analysts to have retained a theater nuclear role in the Baltic Sea and the Sea of Japan. They were withdrawn from service by 1990. After the end of the Cold War, North Korea in 1993 acquired several Golf-class SSBs from Russia, which was in the process of reducing the size of its fleet.
According to a November 2014 article by the Yonhap News Agency in South Korea, citing South Korean officials, the North Koreans had modified one Golf SSB and launched the submarine. Two previous attempts to launch a missile from the submarine since 2015 failed.
It is unknown if North Korea has succeeded in developing a warhead for the KN-11, which is smaller than the nation’s land-launched ballistic missiles, but the country has claimed that it has miniaturized a nuclear warhead.
An SSB, by its ability to deploy at sea and maintain covertness much of the time, would make it a more difficult target to destroy. Diesel-electric submarines, even ones as old as the Golf, are difficult to passively track when submerged and their snorkels are difficult to detect in choppy waters such as the Sea of Japan. North Korea has a sizeable fleet of old Soviet Romeo-class diesel-electric submarines whose presence could make it difficult for anti-submarine forces to isolate a Golf SSB from other submarines.
The ability to deploy nuclear-tipped missiles at sea would enable North Korea to pose a threat from various axes to Japan and South Korea and their U.S. bases, making detection and countering of a launch more difficult. The U.S. Navy and the Japanese Maritime Self-Defense Force maintain patrols of BMD destroyers equipped with the Aegis Combat System and Standard missiles. South Korea has deployed Patriot missiles and has decided to deploying the Terminal High-Altitude Area Defense BMD missile, but facing a threat from yet another direction would tax its defenses even more.
An SSB also is able to move closer to an enemy’s shore and reduce the time of flight for its missiles, reducing the reaction time for defenses.
“This development would potentially give the DPRK [Democratic People’s Republic of Korea] a relatively secure second-strike capability,” said Bryan Clark, a naval analyst with the Center for Strategic and Budgetary Assessments, a Washington think tank. “This could reduce the value of the U.S. nuclear deterrent against the North Koreans. That would be significant, particularly in relation to our extended deterrence assurances to Japan and the [Republic of Korea]. If the DPRK were to threaten one of them with nuclear attack, the U.S. strategic arsenal could not prevent the DPRK from launching the strike with its [ballistic-missile submarine].
“The [ballistic-missile submarine] is less of a challenge for U.S. nuclear deterrence,” Clark said. “If North Korea were to attack the United States directly, it would not be able to eliminate any leg of the U.S. nuclear triad and the attack could be small enough to be defeated by U.S. missile defenses.
The United States could then launch a devastating retaliatory strike. The fact DPRK might be able to respond with a small number of SLBMs against the U.S. afterward would not be a deterrent on the U.S. response.
“The DPRK [ballistic-missile submarine] may also introduce a new requirement to find and track it with U.S. SSNs [attack submarines], as we did against the Soviets during the Cold War,” said Clark, a former U.S. Navy submariner. “This would further tax an already stressed submarine force.”
Although in theory North Korea could deploy an SSB off the coast of the United States, it would be difficult in the near term for the country to sustain a credible threat to the U.S. West Coast.
For a North Korean submarine to operate far from home would be a significant change to past practice and would present command-and-control issues to the North Korean government, which keeps its forces on a tight tether.
