North Korea's underwater-launched missile has a longer-range than the missiles the country tested earlier this year and is designed to be launched from a submarine that has a potential to pose a threat to the U.S. allies in northeast Asia, experts said.
"The missile tested ... has a maximum range of more than twice that of the shorter-range systems North Korea has been testing" this summer, said Michael Elleman, director of Non-Proliferation and Nuclear Policy program at the International Institute for Strategic Studies (IISS). "It does not pose a threat to the continental U.S., but once fully developed, it will threaten U.S. allies and interests in northeast Asia."
North Korea conducted an underwater launch of a new ballistic missile on Wednesday that flew about 450 kilometers off the country's eastern coastal town of Wonsan before landing in the waters off Japan. It reached a peak altitude of 950 kilometers, South Korean's Joint Chief of Staff said.
"It's indeed the longest-range, solid-fueled missile North Korea has tested to date," said Ian Williams, deputy director of the Missile Defense Project at the Center for Strategic and International Studies (CSIS). "[North Korea] has not tested this kind of missile since 2016."
Reaching South Korea, Japan
The missile tested Wednesday is considered to have a maximum range of about 1,900 kilometers at a standard trajectory. The range makes it possible to target all of South Korea and Japan's four main islands. The missile is considered the Pukguksong-3, and the last time North Korea tested a Pukguksong-class missile was in August 2016.
North Korea tested solid-fueled missiles this summer, in an apparent attempt to fine tune the technology. Missiles using solid fuel are harder to detect because the fuel can be loaded long before any launches and then be moved.
The mobile characteristic of the solid-fueled missiles makes it possible to upload the missiles on a submarine or an underwater barge before being launched. This is considered an improvement over liquid-fuel missiles, which have to be loaded immediately before missiles are fired.
"This missile is likely based on the Pukuksong-2, previously tested a few years ago," Elleman said. "It appears some small improvements have been incorporated to enhance the missile's maximum range by a few hundred kilometers and to fit into the smaller confines of the submarine launch tube."
Williams said North Korea's goal is to improve solid fuel missile technology and transfer it to intercontinental ballistic missiles (ICBMs), which can reach the continental U.S.
"It's one more piece of evidence that North Korea's growing competency with solid fuel," Williams said. "This knowledge would likely be applicable to a solid-fuel intercontinental ballistic missile, which I believe is Pyongyang's ultimate goal in its missile development."
Missile test results
North Korea said Thursday it had successfully conducted a missile test from a submarine, which differs from a U.S. assessment.
"The successful new type of submarine-launched ballistic missile (SLBM) test-firing comes to be of great significance as it ushers in a new phase in containing the outside forces' threat to the DPRK and further bolstering its military muscle for self-defense," the country's official Korean Central News Agency (KCNA) said. DPRK is North Korea's official name, the Democratic People's Republic of Korea.
Contrarily, the U.S. Joint Chiefs of Staff said North Korea tested a missile from a sea-based platform.
"I am not going to get into specifics to what the actual missile was other than to say, again, it was a short — to medium — range and I would say that we have no indication that it was launched from a submarine but rather a sea-based platform," spokesperson Patrick Ryder said Thursday.
Much of the threat from submarine-launched missiles depends on how advanced the submarine is, experts said.
"If that submarine is noisy and, thus, easily detectable, it may not pose much of a threat to anyone," Williams said. "It would, however, require near-constant monitoring, which would tie up surveillance and undersea assets that might be assigned elsewhere."
Elleman said North Korea has not fully developed its submarine technology to deploy a submarine far off the country's coast.
"North Korea's submarine will not venture far from the [Korean] peninsula, as the country lacks the supporting infrastructure, ships, logistics, and secure communications to operate them at long distance," he added.
North Korea unveiled what it called a new submarine in July as a sign indicating Pyongyang was developing SLBM technology.
North Korea's latest test came days prior to the resumption of the long-stalled working-level talks scheduled to take place Saturday in Sweden. The talks had been stalled since the failed Hanoi Summit in February, and since May, North Korea has been conducting multiple missile tests.
