In the 1920s, Japan began to translate its growing economic might -- after a prior 50-year crash course in Western capitalism and industrialization -- into formidable military power.
At first, few of its possible rivals seemed to care. America and condescending European colonials did not quite believe that any Asian power could ever dare to threaten their own Pacific interests.
Japan had been a British ally and a partner of the democracies in World War I. Most of its engineering talent was trained in Britain and France. The West even declared Japan to be one of the "Big Five" world economic powers that shared common interests in peace, prosperity and global security.
Occasional parliamentary reforms had convinced many in the West that Japan's growing standard of living would eventually ensure cultural and political liberality.
That was a comforting dream, given that by the 1930s Americans were disillusioned over the cost of their recent intervention in the Great War in Europe. They were weary of overseas engagement and just wanted a return to normalcy. A terrible decade-long depression at home only added to the popular American desire for isolation from the world's problems.
Americans sympathized with China's security worries -- but not enough to do much other than hector Japanese military governments with haughty sermons about fair play and international law, and threaten to impose crippling embargoes.
Japan ignored such sanctimoniousness. Instead, it harangued its Asian neighbors on the evils of Western colonialism and the need for them to combine under Japan's own tutorship to reassert their Asian influence in world politics.
The League of Nations did nothing when Japan began colonizing Manchuria in 1931. Westerners seemed more impressed by the astonishing rate of Japanese economic progress and growing armed clout than they were determined to stop Japanese aggression.
By 1941, few Americans were even aware that the Imperial Japanese Navy had almost magically grown more powerful than the Pacific fleet of the United States in every category of battleships, carriers, cruisers, destroyers and submarines. The idea that Japan was waiting for an opportune moment to exploit American weakness, at a time when Europe was convulsed in war, would have seemed absurd to most Americans.
The 1940 American relocation of its Pacific Fleet home port from San Diego to an exposed Pearl Harbor was supposed to deter Japan. But the Japanese interpreted such muscle-flexing as empty braggadocio, if not more foolhardily symbolism.
The attack on Pearl Harbor followed.