Unfortunately, terrorism cannot be fought with search warrants, and courts, and judges. The agents involved are both too expendable and too replaceable. Even if you find them and put them in prison, the political damage inflicted is far more severe than the retribution obtained. To fight terrorism, you must identity the cause of the terrorist and attack that cause. You must attack it extra-judicially. You must make the cost to the terrorist cause greater than the benefit it obtains from attacking you. That's not an easy fact of life for those of us in the West to face. We want nice clean divisions between guilt and innocence. Unless we are willing to see repeats of body parts blown across the street, we aren't going to get that luxury.
Reagan's bombing of Gadaffi's compound in 1986 was an amazingly effective response. It told Gadaffi that the US was willing to kill him and his family in retaliation for his actions. He got the message. Wait. "Kill his family?" Yes. The bombs dropped that night could not discriminate. The US was willing to kill his family over Lockerbie. But if that's what it takes to keep airliners from being destroyed in mid-air, then that is what you do. Better his family dies than the people in the next plane. That is the necessary strategy. It's hard and it's cold. But terrorism is hard and cold. And it's generally secure from the reach of law enforcement. So you have to deal with it the old-fashioned way.
Do we have the stomach for it? Well, one thing is for sure. If bombs keep going off, we will develop the stomach for it.