Gee, and to think that seven years ago we might have had some influence over this. Yesterday, Saudi Arabia booted out Iran’s diplomatic mission after Iranian demonstrators torched the Saudi embassy in Tehran. The escalating tensions have the Obama administration concerned that it might impact cooperation on the anti-ISIS fight, but these tensions go a long way back — and have been exacerbated by Barack Obama’s shift to appeasing the Iranians:

“We believe that diplomatic engagement and direct conversations remain essential in working through differences,” State Department spokesman John Kirby said Sunday. “We will continue to urge leaders across the region to take affirmative steps to calm tensions.”

But the public call for calm papered over long-simmering disagreements over Iran and other matters between the United States and Saudi Arabia, its powerful Middle Eastern ally, and threatened a serious rupture.

Administration officials were privately critical of the Saudis for provoking the weekend’s upheaval with the execution of Sheikh Nimr al-Nimr, a prominent Saudi Shiite cleric who was arrested two years ago and sentenced to death for fomenting dissent against the ruling Sunni royal family.

According to the Washington Post, the criticism flows in both directions:

“Enough is enough,” said a person authorized to convey Saudi thinking on the condition of anonymity. “Tehran has thumbed its nose at the West again and again, continuing to sponsor terrorism and launch ballistic missiles and no one is doing anything about it.”

“Every time the Iranians do something, the United States backs off. The Saudis are actually doing something,” the person said.

That’s the heart of this new eruption in the ancient Sunni-Shi’a conflict. The US had aligned itself with the Sunnis ever since Ruhollah Khomeini took over Iran, not because the Sunnis were moderates — the Saudis certainly aren’t that — but because they were the most rational option. The Saudis wanted to continue to do business in the post-Versailles Middle East order, unlike the Iranians and Saddam Hussein, who wanted to lead a pan-Arab nation but got bogged down in war against Tehran before taking his first step in Kuwait. While the West remained engaged on the side of maintaining the Versailles status quo, the Saudis had no reason to upset the applecart. Even Israel was less of an issue for the Saudis than an easy resource for domestic propaganda.

All that changed when the US began tilting toward Iran. First, they pulled out of Iraq and gave Nouri al-Maliki carte blanche to welch on agreements with the Sunni minority, and all but gave Baghdad to Tehran. Next, the Obama administration fumbled the so-called “Arab spring,” allowing the radicals in Egypt to take over and conducting a coup against Moammar Qaddafi with nothing to replace his regime. Obama and his administration called for Bashar al-Assad to step down but did little to press the matter, and Syria has joined Iraq and Libya as failed states — all three with thriving ISIS centers of power. American policy has set the region on fire, and now the Saudis have very little incentive to play along with Western attempts to keep the lid on sectarian imperialist impulses in the Middle East.

So now the White House wants to express “deep concern” over the diplomatic rupture between Riyadh and Tehran. The Shi’a-Sunni war long precedes the Obama administration, and for that matter the US and the European presence in the Western Hemisphere. However, the sudden shift toward Tehran and the key step of allowing the Iranian mullahs the opening to pursue nuclear weapons has changed all the calculations for the Saudis. The proxy war in Yemen was just the opening bid. The Saudis are not going to tolerate Iranian attempts to undermine their position, and direct force will be almost inevitable now that the US has expended its superpower credit with the Sunnis.

Everyone has “deep concerns” now. Too bad the White House didn’t have those concerns in 2010-11, when they might have made decisions that would have mitigated some of those now.