The US is/was not the local government in Afgahnistan, Iraq or Vietnam. Nor has it ever had a clear definition of what "victory" actually looks like in those places (nor any policy-level understanding or interest in the local culture and political dynamics that might enable it to develop one).

But it's worth noting that no victory was achieved by the insurgent forces that ever lasted in any of those places: the US, so long as it maintained the military will to stay, could bomb and destroy the insurgents indefinitely. It just couldn't tolerate the political cost of why it's people were being sent to die "over there", and a public which was and is dissatisified with foreign civilian casualties inflicted by US military missions.