Even if Egyptian President Hosni Mubarak succeeds in clinging to power, that is not going to change the writing on Twitter, Facebook and Wikipedia that the whole world has been reading: The days of the Middle Eastern autocrats, allied with the U.S. and open to some sort of co-existence with Israel — in fact, of the entire American hegemonic project in the Middle East — may be numbered.

But whether it comes to promoting its values or to securing strategic interests, U.S. clout in the Middle East has been shrinking now to its lowest point since the end of the Cold War when the U.S. had emerged as the only global player in the region: The “peace process” is all but dead. The radical Shiite cleric Muqtada Sadr’s movement has joined an Iran-oriented Iraqi government. The new Lebanese Prime Minister was selected by Hizbollah. Turkey is pursuing a foreign policy independent of Washington and Iran is continuing to flex its muscle in the Levant and the Persian Gulf.

So it was not surprising that the only mention of the Middle East in Obama’s State of the Union Address was a brief reference to the withdrawal of U.S. troops from Iraq — to American retreat from the region.

The political crisis in Egypt – and the no-win policy choices available now to Washington — demonstrates the dramatic erosion in U.S. influence there. The Mubaraks of the Middle East may still be able to count on the support of their militaries and Mukhabarts (secret services). But having lost their legitimacy as national leaders they are threatened by the eruption of a political volcano — masses of young angry people. Their lowest common political denominator that brings them together is the hostility towards the U.S. which had helped keep their reviled rulers in power for so many years, and to Israel, which is perceived to be America’s partner in crime and the oppressor of their brothers and sisters in Palestine.

If Obama decides to save the American client in Cairo by giving Mubarak a yellow light to rescue his regime, he will only guarantee that the U.S. will become the main target for the demonstrators in Egypt and other Arab countries, igniting more anti-American violence and raising the costs of U.S. intervention in the region to the stratosphere.

But if Obama allows Mubarak to fall – even if that takes the form of a peaceful transition of power – the U.S. would not be able to control the outcome of the revolutionary change in Cairo that even under the best-case-scenario is bound to strengthen the power of the Muslim Brotherhood and other Islamist groups.

Preventing the downfall of Mubarak and the collapse of the rest of the pro-American dominos in the Middle East could give the U.S. some breathing space for a diplomatic salvage operation – perhaps through the revival of Israeli-Palestinian negotiation, the co-opting of Syria into the U.S. sphere of influence, and the fixing of our relationship with Turkey — which could help prevent total loss of U.S. power and credibility in the region.

But even under such a best-case-scenario, we need to recognize that we are at the start of a long period in of a big disorder in the Middle East: regimes will fall, nation-states will split, regional coalitions will come and go and new global players will compete with the U.S. for influence. In short, a Middle East in which the U.S. is going to find it more and more difficult to re-establish order.

Leon Hadar is a research fellow at The Cato Institute.