Yes North Vietnam received military assistance from China and the Soviet Union later on in the war, but the NLF had access to very little of that weaponry.<p>There are stories from American soldiers where they were confiscating WW2 bolt-action firearms from the NLF right up until the late 1960s.<p>Algeria is another great example where they kicked the French out of Algeria but had very little backing from a major superpower.<p>The point is that simple firearms can inflict a lot of damage on a highly sophisticated army.