You could probably kill some of them to convince the others to talk.........since we don't have torture or anything.
Agent: "Either talk or you end up like Abdula."
Terrorist: "Abdula did it."
There's a classic scene in the movie "The Untouchables".
The feds raid a bunch of bootleggers (during Prohibition) and a shootout ensues. One of the bootleggers ends up dead on the porch.
When the battle dies down, the cops grab one of the bootleggers and tries to get information out of him. Sean Connery (as a tough Irish cop) starts to rough him up. Squeaky-clean fed Elliot Ness (Kevin Costner) says, "hey, none of that!", and orders him out of the room. They continue to try to get info from the bootlegger, with no success.
Outside, Sean Connery sees the dead guy on the porch, and gets an idea. He lifts the body up and slams it against the window of the room where the interrogation is going on. He yells at the corpse, "talk, talk, dammit! Tell us what we want to know! So... A tough guy, eh? I'll give you to three to start talking -- one! two! three!"
He shoots the corpse in the face, spraying its brains all over the window of the interrogation room. Then he strides back into the room, and the now terrified bootlegger yells, "ok, ok, I'll talk!!"