Please reconcile your point with each of the following:
Richard Reid
U.K. Train Bombings
Spain Train Bombings
Bali Night Club
Egypt's Tourist Murders
Theo Van Gogh
Danish Cartoons & aftermath
Kashmir
The Taliban
Southern Thailand
Somalia on any given day
Chechnya
Kosovo
Philippines
India
Argentine Jewish Community Center
Israel
Hamas v. PA
Mehmet Ali Agca
Sirhan Sirhan
Seattle Jewish Federation
El Al Counter in Los Angeles
French Riots
I don’t argue at all your point that Radical Islam IS the enemy, and that in many cases it can be successful on a cheap.
My point is not to contradict yours, but to point out the importance of oil. Oily money windfall give Radical Islam a) finances to spread the ideology (madrases everywhere) and finance networks (decentralized, independent, different countries, different sources of money); b) inhibit normal development of their countries, resulting in dissatisfied hapless masses fuming at their impotence, blaming the West and providing fodder for Jihadists; c) threat of oil withdrawal pushes already soft from the multiculturalism mush West into appeasement submission and makes all but impossible a united response by the West to practically any (cheap or not) attack anywhere.
Remember Osama’s proclamation about strong and weak horses? Fear of skyrocketing oil prices forces the West to make very measured steps that appear (if not are) the signs of a weak horse.
Without this fear the Radical Islam would still be a threat. But the West would not be conditioned for more than 30 years to tiptoe around islamist atrocities.