By Sam Ryu, Fall 2023 Marcellus Policy Fellow

Statement of Scope: This paper will not cover the recent Hamas-Israel conflict, as much of the research for the paper was done before this conflict occurred. The ACLED data used throughout this paper does not cover incidents that occurred after September 15, 2023.

The United States’ unconventional warfare campaign against the Islamic State of Iraq and Syria (ISIS) in Syria, through the Syrian Democratic Forces (SDF), has been largely successful. As long as ISIS in Syria remains degraded and contained, and as long as the SDF remain capable of sustaining unilateral operations, the United States will find it more difficult to justify its military presence in Syria on the basis of the ISIS threat. The main threats to U.S. forces and the SDF emanate from Iran-linked militias and Turkish forces, respectively.

While Iran is a regional threat and countering Iran is a vital national interest, a war with Iran over Syria is not necessarily warranted. Accordingly, Congress must exercise greater oversight into the United States’ irregular warfare activities in order to mitigate the risk of drawing the United States closer to war with Iran over Syria. The 2001 Authorization for the Use of Military Force (AUMF) and the Constitution’s Article II authority, which have been used against Iran in Syria, are inappropriate and too broad, respectively, while other statutory authorities, such as § 1202 and § 127e, possess potential for abuse and mission creep.

It will be sensible to avoid escalation with Turkey to avoid jeopardizing the SDF’s anti-ISIS mission. It is unlikely that Turkey will compromise on its aggressive position against the People’s Defense Units (YPG) and the militant Kurds, and Turkey will likely see the YPG as a greater threat than what it would be without U.S. support. Diplomatic approaches are needed to mitigate Turkish aggression while the United States’ continued support for the YPG should be re-examined. Furthermore, the SDF faces serious internal problems that make the YPG an untenable choice as a surrogate force going forward.

The United States does not have much to lose by withdrawing from Syria in the future. The United States’ network of regional partners can play a more constructive role in promoting regional stability, and a withdrawal from Syria will not significantly negatively impact the United States’ ability to fight a war with Iran. Attempting to remove Syrian President Bashar al-Assad from power will be difficult, given Iran and Russia’s support and interest in bolstering the Assad regime, and given the openness of Turkey and Iraq to normalize relations with Assad.