I just finished a book called After War: The Political Economy of Exporting Democracy by Chris Coyne. He talks about the failure of the U.S. to export democracy generally, but also talked about how Japan is kind of an exception.

He says that part of the U.S.' success with instilling liberal institutions in Japan was because MacArthur (as SCAP) utilized pre-existing Japanese institutions and took Japanese recommendations for their new Constitution to heart (accepting 80-90% of proposed changes). Coyne of course acknowledges that MacArthur had absolute fiat over any of those changes, but says that MacArthur's acceptance of many of the proposals indicated an understanding of the importance of self-determination of the Japanese to create liberal institutions.

Is Coyne mischaracterizing the relationship between MacArthur and the existing Japanese hierarchy, or is his analysis accurate (in a historical sense)?