North Korea just flight-tested new sea-based ballistic missiles  North Korea conducted the first flight test of a new submarine-launched ballistic missile last month, defense officials said this week. The flight test of what the Pentagon is calling the KN-11 missile took place Jan. 23 off the coast of North Korea from a sea-based platform — not a submarine — located off the coast of the communist state, said officials familiar with reports of the flight test. U.S. intelligence ships and aircraft monitored the test and tracked the successful missile firing. Additional details of the flight test could not be learned. A Pentagon spokesman declined to comment on the test, citing the sensitivity of information about North Korea’s SLBM program. The flight test followed a land-based ejection test of the KN-11 in November from a static launcher located at the North’s Sinpo South Shipyard in November. Sinpo is a port city on North Korea’s southeastern coast about 100 miles from the Demilitarized Zone separating North Korea from rival South Korea. The flight test is being viewed by US intelligence analysts as a significant step forward for Pyongyang’s submarine-launched ballistic missile program. The new program was first disclosed by the Washington Free Beacon Aug. 26. Marine Corps Lt. Gen. Vincent R. Stewart, director of the Defense Intelligence Agency, told the House Armed Services Committee Feb. 3 that North Korea’s nuclear weapons and missile programs “pose a serious threat to the U.S. and regional allies.” “Pyongyang maintains that nuclear and ballistic missile capabilities are essential to ensure its sovereignty,” Stewart said in a prepared statement. “Because of its conventional military deficiencies, the DPRK [North Korea] also has concentrated on improving its deterrence capabilities, especially its nuclear technology and ballistic missile forces.” Stewart added that DIA is concerned North Korea will conduct a fourth underground nuclear test in the future. More