(Please help asap, brainliest. I have been stuck on this for forever!!) How did the United States go from a successful containment measure in Korea to a failed war in Vietnam?

Containment policies were able to succeed because the South Korean government supported the US-backed government, because we were able to draft a real peace with the North Koreans, and because the US left troops in South Korea. ... We left troops in South Korea. Not so in South Vietnam.

just finished this it is b. centrifugal force

the conditions that made the byzantine empire vulnerable to attacks by the muslin turks were the sack of constantinople by western crusaders, the conquests of the sultanate of rum, presence of rival kingdoms and finally the set up of fiefdoms at the empire which were owned by the ghazis (turkish warriors).