How long did USA station troops in Germany, how long did U.K. have troops in NI. 20 years just allowed the taliban to train their next set of kids to become fighters….
I think the difference between N.I., Germany, and you can I think include Japan.
I actually think Japan is an interesting comparison as they are quite different from the west culturally yet we're rebuilt by the US relatively quickly and quite successfully from the US point of view...
The issue with Afghanistan is that things like democracy and much of what we are trying to implement there are learned socializations. They have no political or societal infrastructure to build off of. We were trying to make a country do something it has no history of. That kind of evolution takes 100s of years.
On top of that, they have very little educational and social infrastructure so making that change is even harder without these tools.
It just was never going to happen in our lifetimes. The leap we need Afghanistan to take to "assimilate" (I'm half asleep, using it for the lack of a better word at the moment" into a western style democracy and ally in the region, is just so much greater that of N.I. or Germany. I don't think it's applicable to say the length of time 20 years, is why it didn't develop.