After Japanese carrier planes attacked the United States Pacific Fleet at Pearl Harbor on the morning of 7 December 1941 ( 8 December , Manila time ) , Taiwan-based aircraft within 6-7 hours pounded the main bases of the American Far East Air Force at Clark Field in Pampanga , Iba Field in Zambales , Nichols Field near Manila , and the headquarters of the U.S. Asiatic Fleet in the Philippines at Cavite .
Japanese carrier planes attacked the United States Pacific Fleet at Pearl Harbor on the morning of 7 December 1941 .