Military action should be against military targets, for the purpose of disrupting the enemy. Terrorism is against people who are not military targets, for the purpose of instilling fear and with the end goal of effecting political change.
In good faith - are you confused about the difference here, or trying to find the specific dividing line?
I think we might be on the same page. The point being that terrorism is anything that tries to push political ideals contrary to the status quo you wish to either enact or uphold. So then if you label anti-fascism as terrorism, is that not the same as soft admitting to being a fascist?