Sort of an ultra-specific question if you're only asking "Governments supported and/or installed by foreign powers engaged in a civil war, or a war with asymmetrical/insurgent/militia groups, surviving a withdrawal of foreign allies in the midst of hostilities." As very few conflicts actually match that criteria. And generally speaking, foreign allies would only withdraw if a conflict is lost.

But if expanding the boundaries a bit, to countries which held together after receiving foreign aid in a conflict with asymmetric elements, either by avoiding a second conflict or outright winning one;

Iraq survived their conflict against ISIS after the US withdrawal. But then again, they also had a lot of help from the PMF and Peshmerga, which are both more 'asymmetric' type forces.

Democratic Republic of Congo, where a new state which was set up after the First Congo war with the help of several states, fought off massive militant groups in the Second Congo War and remained untoppled, even after the withdrawal of foreign allies.

The former Yugoslavian states which were assisted by NATO all survived the withdrawal of foreign allies. While it was primarily a more 'conventional' war, there was internal insurgent movements such as Srpska, SAO Krajina, SAO Slavonia, etc.

The Third Greek Civil War. Put down a Communist uprising with assistance from the UK and USA, survived their withdrawal.

Most Eastern Bloc states also had Anti-Communist uprisings which were suppressed with the assistance of the USSR, and they remained in power after their withdrawal. Granted that's because the USSR still existed, and when they didn't, they all democratized.

South Korea survived after the withdrawal of UN forces. Once again, this was more of a conventional war, but so was Vietnam, as the NVA vastly outnumbered the VC.

The Liberian Civil Wars saw Charles Taylor's insurgent movement overthrow the Doe government. But then Charles Taylor's forces were defeated by Pro-democracy forces supported by Guinea and Sierra Leone, who remained in power afterwards.

The US invasion of Panama saw the US-installed government remain in power after their withdrawal.

The 1989 Phillipines coup saw government forces put down the RAM movement with the help of the US, and they remained in power afterwards.

The US invasion of Granada saw their Communist government deposed, and a democratic government installed which also remained in power after their withdrawal.

El Salvador had a government installed with backing from the US in a coup. Later they saw large number of US advisors training their forces and making top-level military decisions during their civil war against the FMLN, and remained in power after their withdrawal.

If you expand it to include conventional/government forces winning in 4th Generation/Asymmetric warfare conflicts in general, the list expands more.

So... any additional thoughts on this given the recent turn of events?

I find it triggering when social media posts stuff like 'Vietnam 2.0' or 'the US hasn't learnt its lesson'. On the one hand I see that there's definitely been a lot of mistakes and missteps over the past 20 years. But on the other, such criticism is casting a huge net over an incredibly complex problem with extremely invested parties (intelligence community, folks on the ground on both sides etc.). An insult from armchair critics with next to no understanding of history. Not to say I'd respond to them but I do find my own lack of understanding disturbing.

Are asymmetrical/insurgent/militia based conflicts just that hard to quell? Are conventional and counter-insurgency doctrines just inherently too slow/weak when the enemy has minimal structure?