The US did not have to occupy Japan and deal with rebels - the emperor surrendered unconditionally and the US fed the existing pro-democracy movement while rebuilding the country.
If you look at the US' history of interventions, the common thread is that nations with established pro-democracy movements tend to become stable democracies, and nations where democracy lacks popular support tend to turn into flimsy Republics that easily fall apart when American support is removed.
Occupation is so expensive that it's virtually unthinkable for even a medium-size country to be occupied. There are just too many civilians and too few soldiers.
If you look at the US' history of interventions, the common thread is that nations with established pro-democracy movements tend to become stable democracies, and nations where democracy lacks popular support tend to turn into flimsy Republics that easily fall apart when American support is removed.
Occupation is so expensive that it's virtually unthinkable for even a medium-size country to be occupied. There are just too many civilians and too few soldiers.