America's initial u. s. foreign policy of isolationism and noninvolvement was forever altered by the japanese attack on pearl harbor, after which the strategy was deemed unrealistic.

This statement is true, but not only unrealistic, now impossible. The decades prior to the attack on Pearl Harbor, the American government had been debating and attempting to continue its isolationist roots. At the end of the 1800s, the U.S. was involved in several incursions into the global arena, which were always deemed problematic in that the viewpoint was to take care of America by itself, within itself, isolationism. The lack of immediate involvement in World War I demonstrates this, and again here at the beginning of the U.S. involvement in World War II. The U.S. again had resisted the urge to be directly involved in the spheres of war happening in Europe and in Asia, but the Japanese had so antagonized the U.S. with their devastating attack on Pearl Harbor, that involvement in the war was now almost an obligation. With the U.S. having been involved in so many arenas of battle, their policy of isolationism quickly changed to one of capitalistic imperialism in order to obtain and plunder resources throughout the world.