I always find it interesting how the narrative of Tamil Tigers and similar cases boils down to, they both did terrible things and one side (usually the one with more guns) came on top – end of story.
What happened to Tamils in the event you describe is not much different from what happened in genocide-like destruction of Srebrenica and its inhabitants in the hands of Serb army.
It still perplexes me how is it that these two events are totally differently understood in the “West”.
Trying to weed out terrorist by killing, especially when done by invaders from another country, just breeds more terrorist to avenge there fallen friends family or comrades. It may keep the numbers down while activity hunting but is not a final solution.
The British also managed to defeat Boer guerrillas after a long and bloody campaign. Their solution: sweep the country bare of everything that could give sustenance to the guerrillas, which meant rounding up all women and children into concentration camps and conducting a scorched-earth campaign to deny them any supplies.
Theoretically, we could use similar tactics to defeat the Taliban, but the enormous cost, both in human lives and political fallout, makes it untenable. Hence our current quagmire.