Communism was on a rise in North Vietnam under the leadership of Ho Chi Minh. North Vietnam helped the NLF of South Vietnam to overthrow the dictatorial rule of Ngo Dihn Diem. They also decided to overlook the terms of the Geneva Conference and unify Vietnam.
The spread of Communism was viewed as a potential threat by the capitalist nations especially the US. US sent in their troops to South Vietnam to intervene and this was the start of the catastrophic US Vietnam war.
Chemical weapons like B52s Agent Orange, Napalm and Phosphorous Bombs were used which wiped out villages and razed down forests. The US decision to intervene in Vietnam was criticised vehemently back home.
Despite the advanced technology and excellent medical facilities, the US suffered a lot of causalities in the war. The US had completely underestimated the strength and determination of nationalist Vietnamese people.
The Vietnamese used their limited resources to gain maximum advantage over the US. The Ho Chin Minh Trail is a perfect example of Vietnamese enterprise. This trail was a massive network of footpaths and roads, used to transport men and materials from North to South Vietnam.
The US regularly bombed the trail to disrupt supplies, but the trail was managed efficiently and it was rebuilt quickly. Vietnam bravely combated the US attack and got freedom in 1975.