Since President Trump announced that he was kicking around the idea of leaving Syria, many people have naturally asked: Why is the United States in Syria at all? A question, oddly enough, no one seemed interested in asking when President Obama first went into Syria in the air in 2014 or during the two years President Obama’s administration intervened in and occupied Syria. The official answer is simple, but the unofficial version is quite complicated.

Officially:

Officially, the United States entered Syria on the ground in 2015 to take away a safe haven for the Islamic State of Iraq and Syria (ISIS) and destroy any and all revenue streams. “Degrade and Destroy” was the slick branding the Obama administration slapped on the operation, and the public bought it. Now, President Trump uses the same justification for staying in Syria. The job, as they say, is not finished.

In reality, there are some small pockets of ISIS-held territory left in Eastern Syria, but for the most part, they have been decimated and many thousands sent fleeing to new parts of the world to wreak havoc on new fronts. The primary reason America remains in Syria is to prevent the return of ISIS and their symbolic caliphate. For the cynical observer, it may be hard to accept this justification, but it’s true: Bashar Al Assad can’t control or police his eastern desert where the Islamic State thrives.

In fact, the United States is the only military that really possesses the capabilities to project power into that specific area. While there have been isolated skirmishes here and there, Russia has never engaged IS to the east beyond of Palmyra. Russia would love to sweep through the east and triumphantly restore Syria to its pre-revolution self, but it just doesn’t have the muscle.

America’s official justification is a legitimate one. Continue destroying the ISIS and hang around so they can’t come. This is why the Euphrates River makes for an ideal demarcation line. It’s big, it doesn’t move, and it’s impossible to miss.

Unofficially:

What everyone knows, but no one says, is the United States is sitting in Syria daring Iran to make them leave. The U.S. has no legal justification to be in Syria, as the UMAF of 2001 does not extend to engaging the Assad regime. This is the murky complicated bit; the United States didn’t liberate areas from the Assad regime, it liberated areas for the Assad regime and is under no obligation to return those areas to the dictatorial rule of a tinpot despot propped up by Russia thugs.

Iran is eager for the U.S. to leave but is not eager to use force to make that happen, because the Iranian regime’s ultimate regional foreign policy goal was, is, and will always be destroying the State of Israel. “For the shrine” is something Iranians and Iranian backed-militias will claim on tape and social media they’re in Syria to preserve holy Shiite sites, but in actuality, the Iranians are looking to establish a closer staging area to attack Israel. Pushing the U.S. out of eastern Syria does not equal pushing the U.S. out of the Middle East altogether. That tall task begins with the Fifth Fleet in Bahrain, and realistically there isn’t a military on this planet that could dislodge the Americans from that naval facility.

Leaving would allow Iran a symbolic victory and a chance to rally Iranians unhappy with their country’s foreign policy adventures to their cause. Staying keeps the pressure on Iran from within, keeps them from taking over revenue sources, and demonstrates just how inadequate the Iranians are in the face of American military might.

The most complicated variable in this equation is America’s NATO ally, Turkey. Officially they oppose Assad, and by extension Iran, but they were helping Iran get around U.S. sanctions. Turkey has feuded for some 300-odd years with Russians but has recently normalized relations with their traditional foe, undercutting America’s leverage in bringing the civil war in Syria to a quicker end. They claim to fight against jihadis in Syria, but they allowed, knowingly or not, IS to use their border to bring foreign fighters in and export their ill-gotten oil.

When the Turks announced their plans to go into Syria, it was both to protect Sunni Arabs being bombarded by Russians and Assad air power as well as to pacify elements of the Kurdish Marxist known as the People’s Protection Unit (PKK). Turkey considers the PKK its number one threat to national security and was furious when the Obama White House announced they would arm and train members of the YPG, the Syrian affiliate of the PKK. How did Obama calm the waters with Turkey after arming their biggest threat? The U.S. added some Arabs to the mix and changed the name of the Kurdish YPG faction to the Syrian Democratic Forces (SDF).

Yes, it is easy to get lost in the acronyms. and they change all the time.

The secondary justification for staying in eastern Syria is to stop our NATO ally, Turkey, from attacking a proxy the U.S. armed, SDF, to gain even more populist support. The U.S. is basically playing bouncer along the Euphrates River and in the south at the border crossing Al Tanf. In diplomatic theory, the U.S. should be able to make a phone call to the Turks and work all this out, but the reality is Turkey has far more in common with Iran and Moscow than it does with its western NATO allies. The most notable common ground the trifecta has is its general anti-Western sentiment that fuels their respective domestic power. Russia and Moscow have strongmen that play up their own necessity to prevent Western influence while Iran is a revolution still running on fumes based on grievances against the West.

At some point, NATO will have to come to terms with this reality, which is something the current White House doesn’t seem to have any interest in doing. The job of trying to explain all this to an openly uninterested commander-in-chief is not an enviable task, but the U.S. cannot simply cut and run from Syria. It would ignite a chain reaction that would escalate an already bloody war. It must, for the time being, hold the lines it has established until a better solution presents itself.