There are numerous factors behind the victory of Vietnam against the USA. Surprisingly the Vietnam War was lost by the US forces not because of the military might of Vietnamese forces. It is more of numerous actions and decisions made by the US at different that ultimately paved the way for victory for the Vietnam, or the Communist Vietnam to be specific.
I will discuss some of the key factors that I think played a crucial role behind America's defeat.
- Communist Vietnam did not fight a conventional war with USA. The guerrilla tactics with the overwhelmingly powerful US force served their purpose to prolong the war and cause more damage to the US and the South Vietnam.
- Communist North received huge military support from the Soviet which is definitely one of the key reason behind US’s defeat.
- Communist Vietnam’s ideology was highly charged with the Nationalism. It helped to boost the moral reason for Vietnamese to fight with the occupiers or invaders (US Force) to achieve their independence. They went through thousands of year’s Chinese oppression and then later French occupation. They had it enough to fight with just about anybody to gain their Freedom at any cost.
- Ordinary people of South Vietnam did not fight the war rather it was their military which fought on their behalf. On the other hand North Vietnamese soldiers were the civilians (pheasants and others) trained to fight a long war at a cost of millions of lives. South Vietnam didn't had the kind of urgency that north felt in terms of getting rid of occupiers.
- Overall strategy of US failed to understand the Vietnamese people and their culture. Winning the "heart and mind" wasn't successful either as much as the effort to rebuild South Vietnam failed. On the other hand North’s leaders better understood their people and their expectations from the War.
- Paris Peace Accords gave ample amount of time for the North to regroup and re-arm. Exploiting this agreement they took the advantage which wasn't quite the case for the South. While America was keep promising for help to the South, nothing really happened when the help was needed the most by the South. North moved on with their target to capture the South.
- US's internal politics which made Vietnam War unfavorable at home. Politicians made decision on behalf of the Generals. In other words, US military didn't quite do their job as they were suppose to. Strict Rules of engagement, fragging and other internal causes played crucial roles as well.
- Last but not least, the US withdrew their soldiers from the South and slowed down the re-arming process of the South. Vietnam War wouldn't have been over if US didn't withdraw regardless of the fact that US was winning major fights. So basically "pulling out" is another term of admitting defeat.
It is quite impossible to pinpoint every single reason behind US's defeat at Vietnam War. However, these are some of the factors that I found it to be crucial.