A Japanese Maritime Self-Defense Force helicopter carrier joined a U.S. Navy vessel in the Pacific on Monday for the first protection mission under security legislation that took effect last year, with tension running high in the region over North Korea.The mission, being conducted by the helicopter carrier Izumo, Japan's largest postwar naval vessel, is apparently aimed at demonstrating the robust Japan-U.S. security alliance and deterring North Korea from conducting nuclear and missile tests.Prime Minister Shinzo Abe's government has expanded the role of the Self-Defense Forces through th…READ FULL ARTICLE