How did Donald Trump change US rules of engagement in Syria after 2017?
Executive summary
Donald Trump presided over an operational shift in Syria that combined a more kinetic air campaign and looser battlefield discretion with episodic political reversals and retained elements of previous legal frameworks; his administration increased strikes and authorized junior commanders greater latitude while simultaneously keeping US troops embedded with Kurdish partners to prevent a jihadi resurgence [1] [2] [3]. The result was a muddled but real change in how the United States chose to apply force in Syria after 2017: more aggressive, sometimes less transparent, but not an across-the-board abandonment of prior safeguards [1] [3].
1. More bombs, more permissive targeting: a tilt toward kinetic pressure
The Trump years saw a marked increase in coalition air strikes and a command tone that framed the campaign against ISIS as one of "annihilation," which translated into heavier use of large munitions in urban fights—Airwars data and reporting cited nearly 50% more coalition strikes in Iraq and Syria in 2017 and described a preference for large 500 lb-class bombs in dense population centers [1]. Analysts and military insiders reported that rules were relaxed to let more junior officers call in instant air support, a doctrinal shift that effectively broadened battlefield discretion and accelerated the tempo of strikes [1] [3].
2. Targeting: from Assad’s red lines to selective restraint
The administration oscillated on how to treat Syrian regime actions versus terrorist threats: it struck Syrian facilities with Tomahawks in response to chemical attacks, signaling willingness to use force against Assad for specific violations, yet in other instances the White House sought to distinguish threats emanating from Syrian territory from the Syrian state itself—an effort described as a recalibration to avoid automatic attribution of all violence to Damascus [4] [5]. Those strikes demonstrated an expanded set of triggers for force—chemical weapons use being one—while political messaging sometimes attempted to limit the scope of retaliation to narrowly defined provocations [4] [5].
3. Embedded forces and the policy of prevention over withdrawal
Despite campaign rhetoric about pulling back, the administration committed to keeping US forces in northeastern Syria embedded with Kurdish partners to "prevent a jihadi resurgence," institutionalizing a small but persistent footprint that constrained full withdrawal and effectively made counter‑ISIS stabilization a continuing mission [2]. That posture meant US rules of engagement had to accommodate persistent small-unit operations alongside air campaigns and political pressure, blending counterterrorism and stability objectives [2].
4. Command tone, opacity, and civilian harm concerns
Observers and scholars argued that while many formal safeguards from earlier administrations were retained, the operational needle moved toward a more kinetic approach that raised risks for civilians; critics cited increased civilian casualties and a lack of military transparency about how engagement rules were changed or applied [1] [3]. Academic analysis concluded that generals shifted operations toward heavier kinetic options while rejecting some of Trump’s more extreme proposals, producing a hybrid—less constrained in practice, yet still bounded by many preexisting legal frameworks [3].
5. Policy churn, competing voices, and legal-political limits
Trump-era Syria policy was not a single unified rewrite of rules of engagement but the product of competing actors—secretaries of state, national security advisers, and military leaders—so the administration produced multiple, sometimes contradictory signals on use of force, sanctions, and long-term goals [2] [4]. Legal constraints like the War Powers framework remained relevant in debates about strikes, and the administration both complied with reporting requirements in some instances and operated in a posture critics called less accountable and more opaque in others [6] [3].
6. From military engagement to diplomatic shifts on sanctions (post-2017 arc)
Beyond combat rules, the Trump approach ultimately combined military pressure with alternating levers of diplomacy and economic policy; by 2025 the administration moved to terminate Syria sanctions, showing a longer-term rethinking of engagement tools that paralleled but did not erase earlier operational changes to how force was used on the ground [7] [8]. Coverage of these later moves underscores that changes to rules of engagement were embedded in a broader, evolving political strategy rather than a one-time doctrinal rewrite [7] [8].