You don’t make peace with your friends. You make peace with your enemies.
Unless you actually plan on commiting a full scale and thorough genocide, eliminating terrorists is simply not a viable strategy for defeating terrorism. If you don’t go all the way to genocide, then a sizable portion of the non-terrorists you didn’t kill will become terrorist
I don’t think he is forgetting. This is about purging the military of people who would not be loyal to him.