Final answer:
The National Liberation Front (NLF), also known as the Viet Cong, was the Vietnamese political organization formed on December 20, 1960, aimed at overthrowing the South Vietnamese government and reunifying North and South Vietnam.
Step-by-step explanation:
The Vietnamese political organization formed on December 20, 1960, to effect the overthrow of the South Vietnamese government and the reunification of North and South Vietnam was the National Liberation Front (NLF), often known as the Viet Cong. This group was backed by North Vietnam and was instrumental in opposing the regime of South Vietnamese President Ngo Dinh Diem.
Seeking a reunification of Vietnam under communist rule, the NLF was a driving force behind the insurgency in the South. The United States ,too prevent the spread of communism in Southeast Asia, supported Diem with the hope that he would form a democratic, pro-Western government.
However, Diem's government was marred by corruption and oppressive policies against farmers, Buddhists, and various political opponents, which resulted in widespread dissatisfaction and support for the NLF's cause.