It was tail end of Soviet Union and at the time Gorbachev was too wimp to shut down protests inside USSR much less being ruthless anywhere.

Something like https://en.wikipedia.org/wiki/Deportation_of_the_Chechens_an... was very doable to do in Afghanistan before recent population explosion and could have pacified the country. Obviously impractical with modern sensibilities and current Afghan population size.

What can work to bring country together is ruthless dictator with Stalin, Mao or Ho Chi Min determination. US university professor as president is exactly the wrong person to lead Afghanistan at this moment. If current government falls, Taliban can bring somebody reasonable as head of state and country will evolve to something like Iran. Could be good for everyone involved from Afghan population to other countries.