The experience of the Viet Cong and the inexperience of the American soldiers
The Viet Cong guerrilla tactics were very effective against the American soldiers. They used ambushes, booby traps and after fighting just hid with the peasants in villages. Their fighting destroyed the American soldiers’ morale; generally the Viet Cong were much more experienced in fighting in the jungles as they had also fought the French and the Japanese. Whereas many of the American soldiers were new and were drafted in so had little to no experience of fighting, this was not helped by the fact that they also had extremely low morale. There was also a one-year tour of service introduced where the soldiers would only have to go to Vietnam for a year in hopes to raise morale, this just meant as soon as an American soldier became experienced he would be taken away and it would not help at all.
Chinese and Soviet support for the Viet Cong
The Viet Cong and North Vietnamese forces were fighting to get a communist, what most people in Vietnam wanted. China and the Soviet Union wanted this as well so they helped the Viet Cong with the warfare against the USA. An important difference was that the USA was funding a war very far from America whilst the Viet Cong could easily be supplied with weapons by China or Russia.
Opposition, motivation and morale in the USA
Morale was very low; a big reason for this was the Viet Cong tactics. They were hidden in the jungles and attacks could happen at any time which made them very afraid, many of the soldiers took drugs and even sometimes killed their officers. There was also opposition in the USA such as massive civil rights and student protests. They wanted peace and also did not want to get drafted in to a war they did not believe in and found immoral and corrupt. Media coverage grew at home and people were seeing images of the war which also raised opposition and could have undermined the war effort.
The unpopularity of the South Vietnamese regime
The South Vietnamese regime which was first led by Ngo Dinh Diem, then he was killed and replaced by his generals who were just as bad. The regime was very anti-communist (most people in Vietnam wanted communism), they were very corrupt and did not help the peasants of Vietnam. Furthermore they were not Buddhist and treated the high Buddhist priests with little respect, they were very influential so many people started turning against the regime. They started to help the Viet Cong such as hiding them in their villages.