Which U.S. military operations did the Trump administration expand, continue, or withdraw from between 2017 and 2021?
Executive summary
Between 2017 and 2021 the Trump administration simultaneously expanded certain outward-facing footprints and high‑profile capabilities, continued long‑running counterterrorism and regional missions, and pursued selective withdrawals and drawdowns—most notably the negotiated exit from Afghanistan—while rhetoric and budget increases sometimes obscured operational complexity on the ground [1] [2] [3].
1. Expanded presence and new missions: pushing power into new theaters
The administration increased visible U.S. military pressure in multiple theaters: it authorized additional troop deployments to the Persian Gulf amid tensions with Iran, sending roughly 14,000 personnel to the region to reassure partners and protect facilities [3], formalized an enlarged rotational presence in Poland with an agreement for roughly 1,000 additional U.S. troops and related platforms including special operations and drones [4], and expanded forces at the U.S.–Mexico border—sending over 5,000 troops in 2018—to support immigration and counternarcotics aims [5].
2. Expanded use of lethal force and looser targeting in ongoing conflicts
Operational tempo increased in air and strike activity: the Trump years saw escalations in airstrikes and special operations in Iraq, Syria, Yemen and elsewhere, with administration decisions to change rules of engagement and approve more strikes in the Middle East and North Africa relative to the immediate prior period [6]. The White House also touted the destruction of the ISIS territorial caliphate as a completed mission during the period [1].
3. Continued long‑running counterterrorism campaigns and capacity‑building
Many Obama‑era counterterrorism efforts were sustained rather than ended: U.S. counterterrorism operations in Africa and the Middle East continued, and the Pentagon kept forces engaged in campaigns against ISIS and affiliated groups in Iraq and Syria even as numbers and authorities shifted [3] [6]. The administration also elevated cyber warfare posture—promoting U.S. Cyber Command into a warfighting command—and created an institutional Space Force, signaling continuation and institutional expansion of new mission sets [1].
4. Withdrawals and drawdowns: Afghanistan and selective reductions
The administration negotiated a 2020 deal with the Taliban that set conditions for a U.S. troop withdrawal and presaged the full military exit completed in 2021; this represented the most consequential operational withdrawal of the period [2]. The Defense Department also announced phased reductions and partial withdrawals in other areas, including proposed troop reductions in Africa that commanders cautioned might be excessive given ongoing counterterrorism commitments [3].
5. Budgetary posture versus operational reality: rebuild claims and readiness warnings
The Trump White House framed policy as a military “rebuild” backed by large defense budgets and creation of new services and authorities (Space Force, Cyber Command elevation) [1]. Independent analysis and Pentagon assessments, however, warned of readiness and sustainment gaps—reporting that munitions, fleet size and industrial capacity left the force vulnerable in a high‑intensity China scenario—an argument that complicates the administration’s claims the military was fully rebuilt [7].
6. Caveats, covert actions and attribution challenges
Public reporting captures many overt deployments and strikes, but cannot fully account for covert or classified operations; contemporaneous reporting stresses that some operations and changes in authority (including special operations and CIA paramilitary actions) are difficult to attribute precisely to policy choices versus operational inertia from prior administrations [6]. Analysts note that counting troop totals was affected by changes in Pentagon accounting—excluding certain deployments from headline active‑duty totals—which complicates simple “expanded” or “shrunk” narratives [3].
7. Bottom line: a mixed record of expansion, continuation and selective withdrawal
From 2017–2021 the administration expanded specific regional footprints (Gulf, Poland, southern border), increased strike activity and institutionalized new mission domains (space, cyber) while continuing long‑running counterterrorism campaigns in Iraq, Syria and Africa, and executing a major withdrawal from Afghanistan under a negotiated timeline; competing narratives about “rebuilding” the military and warnings about readiness and covert activity mean the period is best read as operationally active but strategically mixed [1] [3] [2] [7].