North Korea may operate a covert ballistic missile base some 27 kilometers from its border with China, a U.S. think tank said Wednesday.Based on satellite imagery, declassified documents, open-source information, and interviews with defectors and officials worldwide, the Center for Strategic and International Studies said the Sinpung-dong base likely houses intercontinental ballistic missiles capable of reaching the U.S. mainland.The center said its preliminary analysis suggests that there may be a total of six to nine Hwasong-15 or -18 ICBMs -- which are believed to be capable of deliverin…READ FULL ARTICLE