 Complete the following phrase:  The four-day whirlwind trip was launched on September 6, 1963, the same day as a National Security Council NSC meeting, and came in the wake of increasingly strained relations between the United States and South Vietnam. Civil unrest gripped South Vietnam as Buddhist demonstrations against the religious discrimination of President Ngô Đình Diệms Catholic regime escalated. Following the raids on Buddhist pagodas on August 21 that left a death toll ranging up to a few hundred, the US authorized investigations into a possible 