Buddhism's Spread in Southeastern Asia

I believe that Buddhisms spread throughout Southeastern Asia was seemingly innocent, but when you uncover the facts, quite power driven. Japan is the best example of it's power driven qualities, because of the strict rulers. Rulers justified their actions and inheritance of the throne by Buddhism. China also exhibits this Buddhism as a way to gain power. The Toba who ruled northern China during the Northern Wie dynasty (386-534) added Buddhist aspects to their traditionally shamanistic cults and even went so far as to have themselves worshipped as reincarnations of the Buddha. If the people were Buddhist believing, and the rulers were reincarnations of the Buddha, than the people would be more respectful and loyal to the people. Just the same way that the Ancient Civilizations' rulers such as the Shang and Egyptian civilizations had themselves ruled as gods to retain power, the Toba added a new and revised "Mandate of Heaven" to help support their rule. In all three areas: China, Korea, and Japan, Buddhism was brought by monks (monks originating from both inside and out of the country) who had some sort of power and connection to the ruler. Without this Buddhism would not have been spread, or even noticed.