Look at who was president during most of WWII and had used the previous decade to set up the federal government in his image. FDR was a literal communist tyrant in the making. If he hadn't had polio and then died in office, he would have become the American Stalin. Truman might have been president during the actual end of the war, but the institutional inertia of the whole American government was still very much an idol to FDR and his authoritarian statism. It's not at all surprising that they leapt at the chance to have an entire nation to control and manage from the ground up in Japan.
Look at who was president during most of WWII and had used the previous decade to set up the federal government in his image. FDR was a literal communist tyrant in the making. If he hadn't had polio and then died in office, he would have become the American Stalin. Truman might have been president during the actual end of the war, but the institutional inertia of the whole American government was still very much an idol to FDR and his authoritarian statism. It's not at all surprising that they leapt at the chance to have an entire nation to control and manage from the ground up in Japan.