1 mistake of the US and USSR in places like Iraq and Afghanistan is that they never planned to be permanent rulers and these were lands at the edge of the world that few people in Washington or Moscow cared about–world history and facts
There’s no secret formula to defeating an insurgency. What it takes is a commitment from the occupier to devote massive resources to the undertaking over a long span of time. The mistake of the US and USSR in places like Iraq and Afghanistan is that they never planned to be permanent rulers and these were lands at the edge of the world that few people in Washington or Moscow cared about. They had much less skin in the game than the Iraqis or Afghans. So the insurgents could just wait out the occupiers while sustaining low levels of violence. One place where guerrillas were decisively defeated is Taiwan, where Japan successfully pacified the country over the long term with a carrot and stick approach. When Japan annexed the islands from Qing China in 1895, the locals were not happy about coming under foreign rule and predictably rose up. Japan responded with extreme violence. Japanese troops made sure to kill every guerrilla they could find and all of their supporters. Sometimes