Fifth Air Force

Truk was part of the Japanese Mandated Islands ceded to Japan in 1919. A major fleet anchorage was created there soon after occupation, and over the next twenty-five years the Japanese used Truk as their main base of operations for the Southern Pacific.

More than any other Allied garrison attacked on December 7, 1941, the Philippines were an important target for the Imperial Japanese High Command. Japanese Navy and Army bombers from Formosa attacked in the late morning, and achieved the same success their comrades were enjoying over Pearl Harbor.