Faced with the Syrian debacle, Trump administration officials, among others, claim that the U.S. can exploit the weakness of the growing strategic coalition between Russia and Iran, ultimately using Russia to contain Iran in Syria and throughout the Middle East.

The Obama administration had this idea too, and it remains wrong.

Circumstances could arise that might split the partners, but American outreach to Moscow won’t do it. A bigger question for the U.S. right now is whether we can prevent other nations vital to our interests from shifting toward the new Russian-Iranian orbit.

There are reasons why the Russia-vs-Iran fantasy is attractive. Historical tension between Iran and Russia is real, and neither state knows how to be a good ally. Russia sees itself as a superpower and disdains to treat other states as equals.

Iran sees itself as the natural hegemon of the Middle East and leader of the vast Shi’a Muslim denomination. Marginalization and persecution of Shi’as over the centuries makes it hard for the Islamic Republic to trust outside powers. Tehran also has had tensions with Russia over Caspian Sea resources and oil.

Thinking too much about these historical disagreements, however, obscures the deep commonality of aims shared by Moscow and Tehran--driving the U.S. from the Middle East being the chief of these common goals.

Iran’s leaders constantly assert that the Middle East should be free of the influence of outside powers. They never point that argument at Russia or China, but rather at the U.S., Britain, and their allies. Russia’s leaders and doctrines assert that the U.S. must abandon its position as a global power and yield to a multipolar world order in which Russia is its equal.

Russia and Iran also share allies and goals around their periphery. Both back Armenia over Azerbaijan in the Caucasus. Russia has kept a military base in Armenia since the end of the Cold War, while Iran fears that Azerbaijan could attempt to stir up separatism within Iran’s large Azeri population. Both seek stability in Afghanistan and prefer to work with local Tajiks, Uzbeks, and Hazaras rather than Pashtuns. Both have, however, worked with, and even supported, Taliban factions when it suited them.

Only extreme circumstances will split the Russo-Iranian coalition in Syria—if the Assad regime faces defeat, or the pro-regime coalition succeeds enough that it can move on to consider its next goals. Neither is likely.

Vladimir Putin would give up on Bashar al Assad long before Ayatollah Khamenei would, but right now Putin needs an Alawite government like Assad’s to let him keep his new military base on the Mediterranean. Ayatollah Khamenei needs the Assad regime to give the Revolutionary Guards’ Qods Force and its Hezbollah allies a secure rear-area from which to confront Israel.

Russia needs Iran in Syria at least as badly as Iran needs Russia.

The Assad regime and army are kept alive artificially by tens of thousands of Iranian, Hezbollah, Iraqi Shi’a militia, and Afghan and Pakistani militia troops, all provided, paid for and commanded by Iranians. The Russians neither can, nor would, replace these forces with their own. If the Russians agreed to drive the Iranians from Syria, the Assad regime and Russia’s position would collapse.

Russian and Iranian aims in the region diverge significantly on two points. The Islamic Republic is committed to destroying Israel and containing or collapsing Saudi power. Moscow shares neither goal. But Moscow has done nothing to protest or contain Iran’s harassment of Israel using Hezbollah and HAMAS.

The Russians have also reached out to the Saudis and Gulf states to mitigate damage their support for Iran has done to their position in the region. Moscow would prefer a Sunni power to balance Iran, where Tehran prefers unquestioned hegemony.

There is some surprising overlap even in this divergent effort, however. Egypt is drifting away from the Saudi bloc and toward Moscow and even Tehran. President Abdel Fattah el-Sisi voted for Russian initiatives in Syria at the U.N. and even sent a small number of Egyptian troops to Syria on behalf of the Russo-Iranian coalition.

The Iranians have no quarrel with Sisi, and have never directed against him the kind of vitriol they reserve for the Saudis and their Gulf Arab allies. Russia and Iran may, in fact, come to see Cairo as a mutually acceptable contender for leadership of the Sunni Arabs in the region at the expense of Riyadh and Abu Dhabi. This would be a formidable new challenge to American strategy and statecraft.

American policy-makers must get past facile statements about the supposed limits of Russian and Iranian cooperation and back to the serious business of furthering our own interests in a tumultuous region.

The Russo-Iranian coalition will no doubt eventually fracture, as most interest-based coalitions ultimately do. Conditions in the Middle East and the world, however, offer no prospect of such a development any time soon.