Among the achievements of the Allied Occupation of Japan after World War II were the successful demilitarization of Japan and the laying of the foundations for the development of truly democratic institutions in Japan. A major element in the democratic process was the Japanese Constitution of 1946, which replaced the less than democratic Meiji Constitution.

Some Japanese argue that the 1946 Constitution is invalid as it was imposed on Japan by Gen. Douglas MacArthur. But the Meiji Constitution of 1889 was imposed on the Japanese people by Meiji oligarchs in a high-handed manner. It was described as having been granted as a favor to the Japanese people by the Emperor, who was "sacred and inviolable." It was authoritarian in nature and designed to bolster the Emperor's powers and prestige. The Emperor, who was described as the nation's "spiritual pivot," was the only person who could amend the Constitution.

If Japan was to play a peaceful role after the war and develop into a real parliamentary democracy, the Meiji Constitution clearly had to be rewritten. The first draft produced by a Japanese committee did not provide an adequate foundation for democratic processes to take root in Japan. An American committee then outlined what was needed and the final Japanese draft followed the basic concepts set out in the American draft. This Japanese draft, in which there was substantial Japanese input, was debated at length in and approved by the Diet. The Meiji Constitution was never debated in or approved by the Diet