How?

1. Long term massive intelligence operations with strong emphasis on HUMINT. Instead of placing troops on Saudi soil we should riddle the Fertile crescent with friends and allies willing to communicate every anomalous thing they see to handlers. Add hightech intell as well facial recognition software coupled with a lot of optical sensors. MAssive databases of connections and relationships between people. Financial analysis and identification. Find them, learn their patterns, learn who they are and to whom they report.

2. A series of careful SOF ops which take out the actual players in the terrorism game, no matter where located.

3. A lot of well-designed public relations allying us with Islam and an effort to return it to those who believe itsbest principles, rather than using its language to support a bunch of hate-filled fatwah booshwah!

That's the high level sketch of how to do it.

A