Even before South Korea came under U.S. influence, Buddhism in Korea has been weaker than in Japan for a long while because neo-Confucianism took over as the state ideology in the early 15th century. Neo-Confucianism emphasizes going out into the world and contributing to the public good, not withdrawing into a hermitage. Most of the great Buddhist monks that people remember are from before the switch. Buddhism was often actively suppressed, and tolerated at best, for the last 600 years.