A recent (1/18/16) article by Doug Bandow, a senior fellow of the Cato Institute, titled “Saudi Arabia Is More Dangerous as a Frenemy than Iran is as an Adversary,” details the havoc wrought not only in the Middle East, but in Europe and the U.S. by U.S. administrations, and especially by the Bush administrations, treating Riyadh as a supposed ally.

It has been known for some time that there was a cozy financial connection between the Bushes and Saudis.  This was well-documented in Craig Unger’s book (2004), House of Bush, House of Saud: The Hidden Relationship Between the World's Two Most Powerful Dynasties.

Here is the review of Unger’s book in the Guardian (2004):

… for the most part this is a very powerful, well-researched and sober book that leaves the reader both enlightened and more than a little disturbed. You will certainly view the Bush administration – and, indeed, American policy-making – through a rather different prism[.]

What the Bandow article adds is the consequences of U.S. administrations, and the Bushes in particular, turning a blind eye to the vicious home rule and Middle Eastern ambitions of the 7,000 ruling Wahhabi-driven Saudi families.  In the case of the Bush family, this was done in conjunction with sub rosa financial support for their various investment activities:

In all, at least $1.476 billion had made its way from the Saudis to the House of Bush and its allied companies and institutions.

As to what the Saudis were up to in return, here are some excerpts from the Bandow article:

The Kingdom of Saudi Arabia is essentially a totalitarian state which acts as a tool of plunder for some 7000 princes and their families. … Unfortunately, Riyadh doesn't keep religious repression at home. The licentious royals long ago made a deal with fundamentalist Wahhabis to enforce repressive Islamic theology at home and fund its propagation abroad… the royals consistently triumphed, brilliantly manipulating the U.S. to advance their interests… By turning the American military into the Saudi royals' bodyguard, Presidents Bush, Clinton, Bush, and Obama spurred terrorism and attacks on Americans. The first Gulf War was directed more to safeguard Saudi Arabia than liberate Kuwait… The monarchy's relationship with the Bush clan, including both Presidents H.W. and George, was particularly intimate.

Here is an account of the basic thrust of the Saudi Wahhabi agenda by none other than Thomas Friedman of the NYT:

Nothing has been more corrosive to the stability and modernization of the Arab world, and the Muslim world at large, than the billions and billions of dollars the Saudis have invested since the 1970s into wiping out the pluralism of Islam -- the Sufi, moderate Sunni and Shiite versions -- and imposing in its place the puritanical, anti-modern, anti-women, anti-Western, anti-pluralistic Wahhabi Salafist brand of Islam

Indeed, while it was not just the Bush administrations that became enablers of the Saudi agenda, given that patriotism and forthrightness were the supposed hallmark of the Bush clan, collusion for financial gain, in spite of its ongoing disastrous consequences, is especially disheartening.