https://www.gatestoneinstitute.org/19775/us-troops-syria
The primary agenda of the Russian-Iranian meeting was reportedly “to discuss expelling the United States from Syria, which may indicate Russia’s intent to facilitate Iranian-backed attacks on US forces.”
Above all, the US presence is important as a blocking force to deny Iran an uninterrupted land bridge to Lebanon and the eastern Mediterranean, and to check the Iranian regime’s long-term expansionist dream of “exporting the revolution.”
Iran already effectively controls three countries in addition to its own – Iraq, Lebanon and Yemen – and has been broadening its influence throughout Latin America.
Any drawdown of the US troop presence at al-Tanf will also tempt adversarial “great powers” in Syria — such as Iran, Russia and especially Turkey — to attack US allies in the region, starting with the Kurdish-majority Syrian Democratic Forces (SDF).
The US presence, in addition, greatly helps safeguard the liberty of countless Syrians from the tyrannical Syrian regime of President Bashar al-Assad…
The pro-democratic forces in Syria and border regions in Iraq also help to prevent the remnants of the Islamic State (ISIS) from reconstituting itself into a robust terrorist entity, as they have already started to do.
US Assistant Secretary of Defense Celeste Wallander, during her September 2022 visit to the region, characterized the mission of these forces as “to ensure the enduring defeat of ISIS.”
Departure also would likely further decrease confidence in US pledges to defend vulnerable democracies throughout the world. Both Taiwan and archipelago countries in Southeast Asia would probably be the most affected by any US plan that abandoned the Kurds to Turkey, Iran and ISIS.
A withdrawal of US forces from their current Syrian redoubts will almost certainly imperil the sovereignty of Iraq, Syria as well as the mission of Kurdish troops. These missions include: guarding prisons that hold hundreds of incarcerated ISIS jihadists as well as monitoring the expansive displaced persons camp at al-Hol, which hosts tens of thousands of the wives and children of ISIS jihadists.
If the Kurds are not able to execute their mission of suppressing ISIS, the failure would quickly lead to a rapid expansion of the terrorist group.
[C]losure of the US mission in Syria would cause alarm among allies and risk accelerating an already precipitous decline in US influence throughout the Middle East…. There is little doubt that the image of US primacy on the world stage, as after the catastrophic withdrawal from Afghanistan, will deteriorate even further. Ally and adversary alike will seek non-American alternatives to protect their national interests.
Although continued US troop presence in Syria is not without risk, withdrawal from the region would no doubt trigger an even greater risk to America’s interests — while remaining in Syria accomplishes much at minimal cost.