To regurgitate a point I made in another thread, Wahhabism is the root of Islamic extremism. It is precisely the practice of interpreting every word written in the Koran literally. The Christians and Jews haven't done this with their respective bibles for ages(don't nit-pick) and it's time the Muslims evolve too.
However, there's one massive fucking problem: Saudi Arabia.
That country(which was first a Saudi state) was founded on the principles of Wahhabi Islam. The original King Saud who created the first Saudi state did so in conjunction with Muhammad ibn Abd al-Wahhab, aka the man who created the Wahhabist movement. To this very day, Wahhabism is the official interpretation and teaching of the book of Islam in Saudi Arabia. And what's worse; the Saudi royal family bankrolls mosques worldwide(this includes in the USA) to teach this same form of extremist Islam.
And that, ladies and gentlemen, is a huge reason why our president and many other high ranking politicians worldwide refuse to refer to Islam linked terrorists as Islamic extremists, because to do so would accuse the Saudi royal family themselves of being Islamic extremists.
But one thing I can't answer is why so many nations, specifically the US, would go to such great lengths to shield the Saudi's from facing justice. Bombs were dropped on Iraq, Afghanistan, Syria, and Lybia for far far less than what the Saudi's have done to America and its allies.