The initial successes were on an unprecedented scale. The entire Far East seemed to collapse all at once after the destruction at Pearl Harbor. In 72 hours of war, Japanese forces had destroyed or disabled the US Pacific Fleet's battleships and had sunk the British warships Prince of Wales and Repulse. Their bombing had blasted most of the US air strength in Hawaii and the Philippines. They were attacking Hong Kong and Manila, and it was only a question of when those cities would fall. And they had assembled their forces for a drive against Singapore.

By the end of the year, the Japanese had almost complete control over the Philippines, had driven MacArthur's troops to a heroic last stand on Bataan and Corregidor, had taken Hong Kong, landed in Borneo, moved into Thailand, and were preparing an invasion of Burma and the Malay States that would end in the capture of Rangoon and the fall of that 'impregnable fortress', Singapore.