The Countries Behind the Vietnam War
The real reason the North Vietnamese prevailed and won in the Vietnam War was because of the Soviet Union (aka Russia) and Red China (aka China). Had it not been for unstoppable military and other aid given to the NVA and VC, perhaps there still would have been a South Vietnam.
The Vietnam War was a proxy war with the USSR and Red China supporting the North and the US supporting the South. It was a fight against Communism by proxy. From 1965-70, Red China (the same China that now makes everything, Made in China) provided North Vietnam with $200 million in aid, while the Soviet Union, some $420 million in aid every year. Cambodia played an important role in receiving the Soviet aid. Soviet ships would travel from ports in the Black Sea, across the Mediterrean and through the Suez Canal. They would dock at the Cambodian port of Sihanoukville, unloaded and then traveled on Soviet trucks via the Sihanouk Trail, which was an extension of the Ho Chi Minh Trail. Almost 80% of the NVA supplies traveled through this port. When the NVA forces started to receive Soviet T-55 tanks in the late 60s, they built (with Soviet help) a fuel pipeline of six inches in diameter from North Vietnam, through Laos and into South Vietnam near Kontum. No small feat.
In 1970, US and ARVN forces invaded Cambodia, finally. There was a lot of negative news coverage in the US as massive B-52 bomber attacks decimated the NVA in jungle hideouts. This was at a time when the first US combat units were being withdrawn from Vietnam. The result of this invasion decimated the key port and the impact was decisive. With the port gone, Soviet ships had nowhere to unload and for the next 14 months, the NVA did very little except rebuild. The Cambodian incursion lasted only for a week or so, then the forces left for South Vietnam. Cambodia claimed it's neutrality, yet the NVA used the trails that went through daily. The Cambodian army was incapable of interdiciting the NVA.
Once Cambodia declared it was neutral, the US had to respect it and any further attacks upon this key port would never happen again. Had the US simply disregarded this and continued attacking the port periodically, the NVA would have never been able to Soviet tanks and rockets in 1973-75 in South Vietnam.
