Just out of curiosity, what makes you think they will ever adjust to the rule of democracy? Left to their own accords, there is nothing to suggest they will keep themselves from voting in a full fledged theocracy or extremist dictatorship, with voting happening along ethnic and religious lines. We could stay there another 100 years and this wouldn't change. Even the Palestinians, practicing democracy, elected a Hamas government. Saudi Arabia, a "pro US govt" uses the Qu'ran as the state constitution.
This is why I think the Japan/Germany analogy is wrong. Taken as a whole, they wanted us there. They knew they needed us. There will never be a secular government in the Middle East as there is today with Germany and Japan. It doesn't take into account the ethnic and religious unrest in the region. When Sunni's and Shiites have been slaughtering each other for 1300 years, I don't think it is reasonable to assume they will ever be able to fully govern themselves in a western style democracy we would find suitable.