What event prompted the United States to become concerned about the spread of communism into the country that would become the independent nation of Vietnam?
A) The rise of Ngo Diem to political power in neighboring Thailand, who was thought to be B) funding communist factions in neighboring Vietnam
C) The shooting down of a US military craft over Southeast Asia by a political group that was believed to be Soviet-backed
D) The fall of French colonial forces in 1954 at the fortress of Dien Bien Phu to rebels, some of whom had communist leanings
The end of a decades-long civil war in Indochina saw the return of pro-communist exiles from China