[2] As dawn moved westward across the Pacific (and the International Date Line), daylight airstrikes followed at mid-day (UTC+12) on Wake Island, at 09:27 (UTC+10) on Guam, at 06:00 (UTC+8) on Davao, at 09:30 (UTC+8) on Baguio and at 12:35 (UTC+8) on Clark Field.

[3] Manila was the United States forward military base in the Pacific, with strategic significance comparable to Singapore for the British Empire.

Lieutenant General Douglas MacArthur commanded United States Army Forces in the Far East (USAFFE) from headquarters in Manila.

Clark Field was the primary air base for the bombers expected to provide offensive airstrike capability under the Rainbow 5 war plan.

[4] FEAF also protected Naval Base Cavite serving as the home port for the cruisers, destroyers, submarines, and flying boats of the Asiatic Fleet.

Clark Field was the primary base for the B-17s, where these heavy planes were stored without camouflage on ramps lest they become mired in the undrained soft soil surrounding those graded surfaces.

[4] United States Army Air Forces commanding general Henry H. Arnold called Brereton that afternoon to ask "how the hell" he was caught by surprise nine hours after receiving news of the Pearl Harbor attack.