It really depend on who is the terrorist. If it is the US govt or armed forces. Run away for safety. I dont know what is the safety zone of US drone ammo. But I just know each ammo is USD 70,000 only. Maybe 1,000 meter diameter is consider Danger Zone. 500 meter is the killing zone.
But if the terrorist is just one person and is white or even a group of them, and if your weapon is only a baton. Run away for safety with anybody you can assist. Lock the door and put obstacles as move to slow down their movement. Call 999.
Pray.
Let other hero fight the terrorist and earn a medal. After all many US soldiers with Purple Heart are homeless. they regret killing innocent people. Trump and uncle sam don't really care. Its only in the movie.
And mind you all US President are terrorist themselves. They order the killing of innocent people, invaded other countries forcefully or anything against the international law.
love all the Americans people regardless which party you support.