sentences:  In 1949, with the Communist victory in the Chinese Civil War, many American missionaries began to depart China for Hong Kong; they were formally expelled in the mid-1950s.At the same time, though, American missionaries in Hong Kong began to play an important role in implementing US policy there, participating directly in the distribution of aid and the recommendation and processing of refugees seeking to immigrate to the United States.However, the United States government itself was ambivalent towards the presence of Americans in Hong Kong; President Dwight D. Eisenhower once suggested restricting visas for Americans in Hong Kong to those who "really had an obligation" to be there, and indicated his reluctance to provide emergency evacuation to American citizens there in the event of an invasion by China.