The difference between war and terrorism is what language you use to say "God wills it"

If you say "Deus Vult", you are a war hero. If you say "Inshallah", you are a radical terrorist.

The rules are quite simple.

it's indeed a distinction without a real difference, but terrorism is specifically targeted at civilians to produce some political outcome.

It's wild to suggest that terrorism against the US should not be responded with by military action - it's only the degree and targets that should be under debate.