I don't really agree - a dedicated populous with light arms in both cases was able to ward off a full victory on their home turf, and the US caved to losses and other pressures (60k dead americans in 'nam, hundreds of thousands wounded physically, notorious trauma uncounted etc).
I don't have any sort of civil war fantasy, but I think that holding out against a military deployment in-country until it became socially and politically untenable would be pretty reasonable.
Sure...in 20 years. The US stayed in Afghanistan for long enough a whole new generation grew up after the occupation had started.
There's many dictatorships which are considerably older then that, yet weapons are easily available or common - Iraqis didn't lack for small arms during Saddam's rule.
I don't have any sort of civil war fantasy, but I think that holding out against a military deployment in-country until it became socially and politically untenable would be pretty reasonable.