This funding is not confined to Muslim countries. The funding goes wherever there is a Muslim community especially a failing mosque, masjid or whatever name the religious building has. There was a masjid in Vancouver run by an Ethiopian Muslim which reached out to Christians, Jews, Buddhists and Hindus. The Saudis locked him out as they they funded this group. So the extremists could come from Europe, North America, Asia or Africa. Wherever the population is exploding and poverty increases the Saudis and Gulf oil-rich states fund Wahhabism to increase their fighting potential soldiers (once they are armed).
Look at Turkey. It was run by secularists till the extremists started increasing. Now it is just a matter of time it will be even more assertive about Sharia Law. Unfortunately the secularists ignored the underbelly i.e. the poor which the Saudis targetted with their 'generosity' to take over Turkey.
Tennyson:
Yours is not to reason why
But to do and die
Definition of a perfect soldier
A religious extremist is an ideal soldier as he not question the religion which is his/her only knowledge and willing to give up his/her life in a holy war.
Come to think of it Mohammed is a man too. He claims to have instructed by the Angel Gabriel but there is no proof. His words therefore are also of human origin and therefore doesn't necessarily supersede man-made laws.