Satellites show N. Korea is amping up nuke program

In a revelation that has strategic implications for Japan, analysis of satellite imagery shows the existence of North Korea's second submersible test-stand barge — a sign that the nuclear-armed country could be ramping up development of its submarine-launched ballistic missile (SLBM) program.

According to the analysis released May 1 by the 38 North website, a project of the U.S.-Korea Institute at Johns Hopkins University, the barge was identified in commercial satellite images taken April 19 of the Nampo Naval Shipyard on the country's west coast.

The isolated nation already operates one barge on the country's eastern coast, at the Sinpo South Shipyard, from where it has conducted at least four — but as many as six — test-launches of the Pukguksong-1, or KN-11, SLBM since 2014, when that barge was first seen.

According to the report, the newly detected barge appears to be identical in size and layout to the original. Such barges are used by navies to test underwater new and modified submarine missile launch tubes and systems, and to conduct initial test-launches before the systems are installed in submarines.

"The discovery of a second missile test barge may have a number of implications for the future of North Korea's SLBM program that appears to be an important priority for Kim Jong Un," the report said, adding that the timing of the barges' acquisition could help reveal the direction of the program.

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If both were acquired at the same time, the report said, it would imply that Pyongyang is planning a more extensive test program than it has conducted so far.

It is unclear if the new barge was acquired or manufactured by the North, but since there have been no indications of barge construction work at the North's west coast naval shipyards over the past year, that suggests the vessel had been acquired from abroad.

"Since the second barge seems to have been acquired three years after the first, this could mean that North Korea is planning to accelerate its SLBM test program to include a west coast component or develop new SLBM designs, or that it may deploy a ballistic missile submarine with the West Sea Fleet," the report said. "None of these possibilities are mutually exclusive."

The Pukguksong-1 would give the reclusive state a credible sea-based nuclear deterrent since the threat of a retaliatory second-strike would throw a wrench into any scenario where the U.S., South Korea, and Japan attempt to preemptively destroy North Korea's nuclear capabilities.

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According to David Wright of the Union of Concerned Scientists, the Pukguksong-1 has a maximum range similar to the North's Rodong missile of about 1,250 km, allowing it reach most or all of Japan from a submarine located near the Korean coast.

However, the North's submarine fleet remains limited in range as it is undergoing a modernization revamp, and would currently be easily detectable by superior U.S., South Korean, and Japanese anti-submarine warfare technology.

Experts say any scenario involving an attempted firing of a Pukguksong-1 from the Sea of Japan by submarine would effectively be a suicide mission for the North.