Israel, oil and military bases to project power are the triad of U.S. strategic interests in the Arab world. And all three are at risk as the region enters a risky new period of disequilibrium.
Egypt, the Arab world's largest and most powerful state and the linchpin of Washington's Middle East policy, is in turmoil, with President Hosni Mubarak pledging to step down after September elections and protesters demanding his immediate ouster.
In Jordan, the only other Arab state that has signed a peace pact with Israel, the King tossed his government over the side in the apparent hope that a pre-emptive strike might stop the rising democratic impulse from dooming his monarchy.
Should Saudi Arabia also find itself in the cauldron of protest, then the three interests that have been central to U.S. policy in the Middle East since the end of the Second World War will be at risk.
Regimes of varying degrees of ruthlessness, Washington's Arab allies have provided relative stability, a reliable supply of the black gold that powers the global economy, and the runways and naval bases that allow unfriendly Arab states such as Saddam Hussein's Iraq to be pounded and hostile powers such as Iran and Syria to be threatened and contained.
While dictators in repressive regimes look on nervously as Mr. Mubarak is edged toward history's bin of ignominiously ousted rulers, the contagion may not spread. Protests in Yemen, Sudan and Jordan do not necessarily signal the beginning of a region-wide revolt. Even if they do, America's interests vary.
While Washington might celebrate if angry masses toppled Syrian President Bashar al-Assad, nothing in the region would be more threatening to U.S. interests than a democratic revolution that ousts the Saudi royal family, which rules with only the thinnest of velvet gloves over the fist of repression.
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President Barack Obama may have relatively little capacity to order outcomes, although he is already being blamed by some for presiding over a massive foreign policy failure.
Just as "Jimmy Carter will go down in American history as 'the president who lost Iran,' … Obama will be remembered as the president who 'lost' Turkey, Lebanon and Egypt, and during whose tenure America's alliances in the Middle East crumbled," columnist Aluf Benn wrote in the Israeli newspaper Haaretz.
Protecting Israel remains paramount, not just because of the powerful Jewish lobby in the United States but because it represents the only real democracy in the Middle East.
But some analysts believe the "loss" of Egypt isn't strategic, even if the Israeli lobby is fearful of a hostile, albeit democratic, government in Cairo.
"This is one of those fortunate moments when the United States does not face a clear tradeoff between its moral sympathies and its strategic imperatives," Stephen Walt, an international relations professor at Harvard, wrote in Foreign Policy magazine. "For starters, Egypt is not a major oil producer like Saudi Arabia, so a shift in regime in Cairo will not imperil our vital interest in ensuring that Middle East oil continues to flow to world markets."
For Washington, the nightmare scenario would be an Arab world transformed not into a bunch of disparate fledgling democracies but into a set of states ruled by Islamic parties hostile to both the United States and Israel.
More likely, the revolutions under way in the Arab world will leave a patchwork of outcomes. Already dim hopes of a Palestinian-Israeli peace seem certain to darken if the shape of the next government in Cairo is unknown.
Certainly, anti-American Islamic parties such as Hamas in the Palestinian territories and Hezbollah in Lebanon will be emboldened if the Muslim Brotherhood emerges as a potent political force in the next Egyptian government.
While oil would likely still flow, the toppling of the Saudi royal family would be the real game changer in the region.
U.S. warplanes and drones fly from bases scattered along the Persian Gulf, many of them in small emirates. Those bases are vital in the Afghanistan war and handy for threatening Iran. Although no U.S. bases are left on Saudi soil, any cooling of Saudi-U.S. relations could imperil bases elsewhere in the Gulf as small states would be less willing to irk the Saudi giant.
It is a strange irony that if - and it remains a big if - America's big, Arab allies, notably Mr. Mubarak in Cairo and the Saudi royals, were both to be ousted by popular uprisings, then Iraq would emerge as the most important U.S. ally in the region, with bases, oil, a strategic location and some vital interests to share with Washington.