Yup, they could teach (and probably have taught) Al Qaida a thing or to!
Starting in the early 60's the IRA started providing instructors for Soviet funded camps in northern Africa and the middle east (at that time Syria). It was only then that effective terror bombing tactics started becoming a primary weapon in the jihadist armory.
It's very easy to trace the bombs killing our people in Iraq back to the efforts of these fine Irish volunteers.