North Korea's SLBM threat looms large Posted : 2021-04-11 16:54 Updated : 2021-04-12 09:11 North Korea's newly developed submarine launched ballistic missile Pukguksong-5 is being introduced at a military parade held Jan. 14, 2021, to mark the country's ruling Workers' Party of Korea's eighth congress, in this photo released by the country's state-run Korean Central News Agency the following day. Yonhap By Jung Da-min Speculation is mounting over North Korea's possible test launch of a ballistic missile from a newly manufactured submarine, according to local defense experts, Sunday, as suspicious activity has been detected at a shipyard that has facilities for testing submarine-launched ballistic missiles (SLBMs).