The following is a passage, on page 52 (paperback edition) of British historian Charles Allen’s interesting book, God’s Terrorists, The Wahhabi Cult and the Hidden Roots of Modern Jihad:
In about 1744 a remarkable partnership was forged between Muhammad ibn Saud and Al-Wahhab (founder of Wahhabism). This was formulated in an oath-swearing ceremony between the two by which the former took upon himself the role and title of emir, or secular leader, and the latter became the imam, soon afterwards assuming the rather grander title of Sheikh ul-Islam. This alliance allowed the one to become a powerful local ruler and the other to transform the province of Nejd by stages into a dar ul-Islam, that much sought after domain of Faith wherein the true sharia prevailed.
In the 1930s, the Sauds became the effective rulers of all Arabia and the pact continues to the present day. Does the U.S. really think that an oath that has stood for two and a half centuries is going to be set aside in a year, just because America doesn’t care for Wahhabism?
One of the problems with the Saudi-Wahhabi version of Sunni doctrine is that the Saudis fund madrassas (Islamic religious schools) all over the globe, tens of thousands of them, and these materials are the root of the students’ understanding of Islam.
For further reading on the threat these madrassas pose to the west, see here and here.