Which brings us to today, more than 50 years later as another US president seems to think that arming Vietnam again with US weapons is somehow a good idea.
As US President Barack Obama announced the lifting of the decades-long embargo on sales of lethal weapons to Vietnam, he seemed at pains to explain the decision "was not based on China or any other considerations".
Yet his mention of China reveals some of the greatest security concerns brewing in Hanoi.
Since a brief but bloody border war in 1979 that cost thousands of lives, Vietnam-China relations have been bumpy to say the least. From being Vietnam's biggest ally, ironically, in the war against the United States, China has increasingly been seen as a dominant, and at times, threatening neighbour.
Recent tensions in the South China Sea have added to the growing mistrust. Vietnam protests against what it sees as excessive Chinese maritime claims and supports the court case brought against China by the Philippines. Not only does China's growing assertiveness in the area challenge Vietnam's sovereignty, it could greatly affect its fishery, oil and gas activities, too.
I'm not sure what President Obama's game here is, but the notion that this is not "based on China" is not complete garbage like it seems at face value, Of course this is about protecting Hanoi from Beijing's navy, happily building their own airstrip islands across the pacific to project power.
But if there is somehow another country involved, it's actually Russia:
It is no secret that Vietnam is trying to boost its maritime defensive capability. Its largest arms contract to date with a foreign country was the $2bn purchase of six kilo-class submarines from Russia.
A large number of patrol and missile ships and fighter jets have also been purchased from Russia, as Vietnam's military spending more than doubled between 2004 and 2013. It is now the eighth largest importer of weapons in the world.
"Better for Vietnam to be buying weapons from us than Putin" isn't exactly the kind of thing Obama should want to be remembered for, but here we are neck-deep in the realpolitik quagmire once again, hooray!
No way this will come back and bite us in the ass or anything. Hey, those US jobs in the TPP have to be paid for by selling some sort of good or service, and that apparently includes military equipment to Hanoi. See, new markets!
New markets, and same old mistakes. Sigh.