Political map of East Asia and the Western Pacific 27 February 1942 (Battle of Java Sea): Allied efforts under ABDA (American-British-Dutch-Australian Command) proved unable to halt the Japanese offensive. In mid-February the vital British naval base of Singapore surrendered (Battle of Singapore), followed 12 days later by the sinking of the main ABDA naval force when it tried to stop the Japanese invasion of Java (Battle of the Java Sea).