In 1988 the Japanese economy was in the middle of the longest financial boom it had experienced since World War II. After Japan lost the war, the American army occupied the defeated country, taking control of the government and steering it toward a new political and economic structure. The Emperor remained on the throne because the Americans wanted to use his presence to oppose the rise of Communism in southern Asia, but political control was shifted into the hands of elected officials. A new Japanese constitution came into effect in 1946, renouncing war forever and adapting a parliamentary democracy. Sovereignty was restored to the Japanese in 1952, in exchange for Japan's withdrawing from countries it had invaded during the war and paying reparations.

After that, Japan grew in economic stature. The first big boost was the Korean War (1950 to 1953) during which Japan provided the U.S. Army with...