Regional Security After Assad: ISIS Resurgence and Competing Militias in Syria and Iraq
Updated December 2025
The collapse of Syrian governmental authority has fundamentally altered the security landscape across the Levant and Mesopotamia. Rather than resolving longstanding conflicts, Assad's fall has unleashed competing forces that threaten to destabilize the broader Middle East. The Islamic State has exploited this vacuum to rebuild operational capabilities, while Turkish and Iranian proxies clash over territorial control, creating a multi-layered crisis that defies conventional counterterrorism approaches.
The Islamic State's Tactical Evolution
Between October and December 2025, Islamic State cells executed 47 documented attacks across Syria's eastern provinces, according to local monitoring networks—a 34% increase from the previous quarter. These operations differ markedly from the group's territorial phase. Rather than holding ground, current IS strategy focuses on targeted assassinations of village mukhtars and tribal elders who cooperate with Kurdish-led authorities, systematic attacks on agricultural infrastructure during harvest season to undermine economic recovery, and kidnapping campaigns that fund operations while demonstrating state weakness.
In mid-December 2025, the security environment deteriorated sharply when a suspected ISIS operative embedded within the new Syrian security forces executed a "green-on-blue" insider attack in Tadmur (Palmyra) on December 13. The assault killed two American service members and a U.S. civilian interpreter, marking the first direct American casualties in Syria since Assad's fall in December 2024. ISIS claimed responsibility for the operation, signaling the organization's strategic intent to exploit vulnerabilities in the newly integrated security apparatus and encourage insider attacks that undermine trust between Syrian and American forces. The incident exposed critical gaps in vetting procedures and revealed IS penetration of transitional security structures.
Current intelligence assessments from December 2025 estimate between 1,500 and 3,000 active ISIS fighters operating across Syria and Iraq. However, these numbers represent only the immediate threat. Detention facilities in northeastern Syria hold approximately 9,000–10,000 suspected fighters and 26,000 family members, creating a reservoir of potential recruits should security conditions deteriorate. The organization has demonstrated patience in rebuilding, understanding that territorial control requires premature exposure to counterterrorism strikes. Instead, IS focuses on preserving cadres, maintaining financial networks, and positioning itself to capitalize on future opportunities.
The group has refined its organizational structure to survive in a post-caliphate environment. Desert hideouts in the Homs-Deir ez-Zor corridor provide sanctuary between Syrian and Iraqi territories. Financial networks have diversified beyond oil smuggling to include protection rackets in reconstruction zones, taxation of cross-border trade through informal routes, and cryptocurrency-based donations from external supporters. Leadership succession mechanisms ensure continuity despite targeted killings, with mid-level commanders assuming authority within days of leadership losses.
The American Military Response: Operation Hawkeye Strike
In response to the Palmyra attack, the United States launched Operation Hawkeye Strike on December 19, 2025—a large-scale air campaign targeting over 70 ISIS positions across central and eastern Syria. The operation concentrated on Jabal al-Amur near Palmyra, the Ma'dan desert in rural Raqqa, and the Hamad desert in Deir ez-Zor governorate. U.S. forces deployed F-15E and A-10 combat aircraft, Apache attack helicopters, and precision HIMARS artillery systems, delivering more than 100 munitions against identified targets.
Jordanian forces provided air support, reflecting regional concern about ISIS resurgence near their borders. Initial assessments indicated at least five ISIS operatives killed, including a cell commander specializing in drone operations. President Trump characterized the operation as "highly successful" and a "declaration of vengeance," while the Syrian Democratic Forces confirmed that sustained American air support remains decisive in preventing ISIS cells from regrouping.
The operation's significance extends beyond immediate tactical effects. It demonstrated American willingness to conduct major strikes in coordination with Syria's new transitional government, marking a shift from the cautious engagement that characterized relations with Assad-era Syria. Damascus issued statements fully supporting the operation and pledging intensified counterterrorism efforts. This cooperation suggests emerging operational frameworks between Washington and the transitional Syrian administration led by Ahmad al-Sharaa, though questions persist regarding the long-term sustainability of U.S. military presence.
Proxy Competition and Territorial Fragmentation
Turkish military operations in northern Syria have created a 30-kilometer buffer zone populated by approximately 140,000 displaced Syrians, according to UN estimates from November 2025. These areas function as Turkish protectorates, governed through local councils aligned with Ankara's Syrian National Army proxies. The arrangement serves multiple Turkish objectives: preventing Kurdish territorial continuity along the border, demonstrating Turkey's indispensability in any political settlement, and creating facts on the ground for potential annexation or permanent influence.
Meanwhile, Iranian-backed militias maintain strategic positions along the Damascus-Baghdad highway corridor. Lebanese Hezbollah forces control key transit points near the Lebanese border, while Iraqi Shia militias garrison sites near the Iraqi frontier. This network provides Iran with multiple capabilities: weapons transfer routes to Hezbollah in Lebanon, forward deployment near Israeli-controlled Golan Heights, economic leverage through control of trade routes, and strategic depth that complicates any potential military action against Iranian interests.
The Kurdish-led Autonomous Administration controls approximately one-third of Syrian territory, including most oil and agricultural resources. This entity faces existential threats from Turkish military pressure, diplomatic isolation as no state grants formal recognition, economic fragmentation as its currency and institutions lack international legitimacy, and internal fragmentation between Kurdish nationalist priorities and Arab tribal interests in majority-Arab territories under Kurdish administration.
Intelligence Failures and Governance Vacuums
The Palmyra attack exposed systematic failures in security integration processes. The perpetrator had apparently passed vetting procedures designed to screen former Assad regime forces joining the new security apparatus. This breach suggests either inadequate screening protocols, insufficient intelligence sharing, deliberate ISIS penetration strategies that positioned sleeper agents within security structures, or some combination of these factors.
Intelligence-sharing mechanisms between competing actors remain minimal—Turkish intelligence does not coordinate with Kurdish authorities despite both ostensibly fighting IS, while Iranian-backed forces prioritize monitoring opposition groups over counterterrorism. This fragmentation creates exploitable seams where IS operates with relative impunity.
Detention facilities holding approximately 56,000 IS family members and 10,000 suspected fighters present a growing crisis. The Kurdish-led Autonomous Administration lacks resources to provide adequate security, legal processing, or rehabilitation programs. Several camps experienced riots during autumn 2025, while escape attempts have increased. These facilities function as radicalization incubators, where hardline ideology spreads among populations living in squalid conditions without legal recourse or repatriation prospects.
Sunni Arab communities in eastern Syria and western Iraq's Anbar province remain alienated from governing authorities. Kurdish-led administration in Syria faces accusations of ethnic favoritism, while Baghdad's Shia-dominated government has failed to provide security or services to Sunni-majority areas. This alienation provides IS with social cover—populations may not support IS ideology but often prefer IS absence of governance to predatory behavior by official forces or rival militias.
Strategic Calculations of External Powers
Iran's investment in Syrian and Iraqi proxy networks serves defensive and offensive strategic functions. Defensively, these forces provide strategic depth against potential American or Israeli military action, creating costs for any adversary considering strikes on Iranian territory. Offensively, they position Iran near Israeli borders, project power throughout the region, and establish Iran as an indispensable actor in regional security arrangements.
Turkish strategy reflects President ErdoÄŸan's conception of Turkey as a regional power with legitimate security interests and historical ties to former Ottoman territories. Military operations in Syria serve domestic political purposes, demonstrating strength to nationalist constituencies and justifying executive power concentration under security imperatives. They also address genuine security concerns regarding PKK infiltration and attacks originating from Syrian territory, though Turkish actions have simultaneously undermined the most effective anti-IS force on the ground.
American policy underwent significant recalibration following the Palmyra attack. The immediate military response signaled Washington's continued commitment to counterterrorism operations despite broader regional realignments. However, the approximately 1,000 U.S. troops currently deployed in Syria exist in an ambiguous strategic environment. They function as deterrents against both Turkish attacks on Kurdish partners and ISIS resurgence, while increasingly coordinating with Damascus on counterterrorism operations.
This evolving relationship between Washington and the Syrian transitional government represents a dramatic shift from previous policy. Partial sanctions relief and emerging cooperation frameworks suggest American willingness to engage with post-Assad Syria, provided Damascus demonstrates commitment to counterterrorism and governance reforms. Yet sustainability remains uncertain—domestic political pressures in the United States continue favoring troop withdrawals, while regional actors pursue competing agendas that complicate American objectives.
Regional Spillover and Humanitarian Consequences
Lebanon hosts approximately 1.5 million Syrian refugees according to November 2025 UNHCR figures, representing roughly 25% of Lebanon's total population. This demographic shift occurs as Lebanon experiences economic collapse, with currency devaluation exceeding 98% since 2019. Competition for scarce resources fuels social tensions, while Hezbollah's involvement in Syria has contributed to Lebanon's political paralysis and international isolation.
Jordan manages approximately 1.3 million Syrian refugees, the majority living outside official camps in urban areas. While Jordan has maintained relative stability, security concerns persist regarding IS infiltration, smuggling networks operating along the Syrian border, and the long-term sustainability of international funding for refugee support programs that prevent further destabilization.
Iraqi Kurdistan hosts approximately 250,000 Syrian Kurdish refugees, primarily in camps near the Syrian border. The Kurdistan Regional Government faces fiscal constraints due to budget disputes with Baghdad, making refugee support increasingly difficult. Meanwhile, IS sleeper cells in northern Iraq's disputed territories exploit Arab-Kurdish tensions and governance vacuums in areas contested between Baghdad and Erbil.
Economic Warfare and Reconstruction Politics
Syria's economy has contracted approximately 70% since 2011, with GDP per capita declining from $2,802 to under $500. The Syrian pound has lost 99% of its value. Pharmaceutical factories, electrical infrastructure, hospitals, schools, and agricultural systems require reconstruction estimated at $400-450 billion—exceeding 50 years of pre-war Syrian GDP.
Yet reconstruction has become a tool of political warfare. The United States maintains Caesar Act sanctions that prohibit most economic engagement with the Syrian government, though partial relief following Assad's fall has created opportunities for limited reconstruction efforts. Gulf states willing to invest face residual American regulatory concerns and sanctions risk. Russia and Iran lack financial resources for large-scale reconstruction despite their military investment. China shows limited interest in significant Syrian investment, focusing instead on more stable and profitable Belt and Road projects elsewhere.
This economic strangulation ensures continued humanitarian suffering while providing IS with recruitment narratives. When populations lack legitimate economic opportunities, extremist groups offering salaries and purpose find willing recruits. The international community's apparent willingness to allow economic devastation as political leverage creates conditions that perpetuate the very extremism such policies ostensibly aim to counter.
Toward Alternative Approaches
The current trajectory leads nowhere sustainable. Managed instability may prevent worst-case scenarios but condemns millions to indefinite suffering while allowing extremism to fester. Breaking this cycle requires acknowledging several uncomfortable realities.
First, no purely military solution exists to the IS threat. Defeating IS territorially did not eliminate its ideology, networks, or appeal. Operation Hawkeye Strike demonstrates American capability to conduct devastating tactical strikes, yet such operations address symptoms rather than causes. Sustainable counterterrorism requires addressing governance failures, economic desperation, and sectarian grievances that provide extremist groups with social bases. This demands political solutions that current actors show limited willingness to pursue.
Second, external powers must recognize that maximalist objectives cannot be achieved without catastrophic escalation. Iran cannot eliminate Israeli or American presence in the region through force. Turkey cannot eliminate Kurdish identity or aspirations through military campaigns. The United States cannot reshape Middle Eastern political systems through limited military deployments. Acknowledging these limitations might enable more realistic diplomacy focused on harm reduction and coexistence rather than victory.
Third, regional stability requires inclusive governance arrangements that provide all communities with political representation and economic opportunity. Sunni Arabs in Syria and Iraq need meaningful roles in governance structures, not merely token representation in systems dominated by other groups. Kurdish populations require political rights and cultural recognition, even if full independence remains unrealistic. Minorities need protection and political space. These requirements conflict with the winner-take-all mentality that currently dominates regional politics.
Fourth, reconstruction must be accelerated to prevent extremist exploitation of economic desperation. The emerging cooperation between Washington and Damascus creates opportunities for conditional reconstruction assistance that incentivizes governance reforms while addressing humanitarian needs. Allowing reconstruction to proceed, even in areas controlled by imperfect transitional authorities, would reduce suffering and extremist recruitment while potentially creating economic interests in stability that transcend current political divisions.
Future Trajectories: Recalibrated Scenarios
With Operation Hawkeye Strike executed and cooperation frameworks emerging between Washington and Damascus, the most probable near-term scenario has shifted from "managed instability" toward "intensive military containment with conditional engagement." This approach depends on several critical factors: sustained coordination between American forces and Syrian transitional authorities; addressing security gaps within government forces through improved vetting and counterintelligence; accelerating rehabilitation programs and economic reconstruction to reduce extremist appeal; and maintaining international commitment to counterterrorism operations while avoiding mission creep into broader Syrian conflicts.
Success would manifest as declining IS attack frequencies, improved security force effectiveness, gradual economic recovery in liberated areas, and sustainable repatriation programs for displaced populations. Failure would trigger escalating insider attacks, IS attempts to liberate detention facilities, renewed territorial gains in ungoverned spaces, or broader regional escalation as competing powers exploit instability for strategic advantage.
The coming months will prove decisive in determining whether IS remains a chronic low-intensity threat or achieves broader resurgence. The Palmyra attack demonstrated that IS retains capability and intent to inflict significant harm through asymmetric operations. The American response showed willingness to conduct major strikes in coordination with Damascus. Whether this reactive approach evolves into sustainable counterterrorism strategy addressing root causes remains uncertain.
Conclusion
The regional security environment in Syria and Iraq represents a complex, interconnected crisis that defies simple solutions or quick fixes. The Islamic State's resurgence reflects not merely terrorist resilience but fundamental failures of governance, legitimacy, and inclusive politics. The December 2025 Palmyra attack and subsequent Operation Hawkeye Strike illustrated both IS adaptation and international response capabilities, while exposing persistent vulnerabilities in security integration processes.
Competing proxy networks serve external powers' strategic interests while undermining state sovereignty and perpetuating violence. Economic devastation creates conditions for continued extremism while reconstruction politics weaponize humanitarian aid. Yet emerging cooperation between Washington and Damascus suggests potential pathways toward more effective counterterrorism, provided such cooperation addresses root causes rather than merely tactical threats.
Breaking destructive cycles requires acknowledging uncomfortable realities, abandoning maximalist objectives, and embracing harm reduction alongside kinetic operations. Whether regional and international actors possess the political will or diplomatic creativity to pursue such alternatives remains uncertain. What is certain is that military strikes alone, however devastating, cannot eliminate extremism rooted in governance failures, economic desperation, and sectarian alienation.
The people of Syria and Iraq have already paid an unconscionable price for others' strategic games and political failures. The question facing policymakers is not whether military force has its place—Operation Hawkeye Strike demonstrated that it does—but whether force will be coupled with genuine efforts to address the conditions that allow extremism to flourish. The coming year will reveal whether current approaches represent genuine strategic evolution or merely tactical adjustments to fundamentally unchanged policies.
References:
- U.S. Central Command (CENTCOM), official statements, December 2025
- Reuters, "U.S. troops killed in Syria insider attack," December 13, 2025
- The Guardian, "ISIS claims responsibility for Palmyra attack," December 14, 2025
- ABC News, "Operation Hawkeye Strike targets ISIS positions," December 19, 2025
- The New York Times, "Pentagon estimates on ISIS strength," December 2025
- Al Jazeera, "Syria's transitional government cooperates with U.S. strikes," December 2025
- United Nations High Commissioner for Refugees (UNHCR), Syria refugee statistics, November 2025
- Institute for the Study of War (ISW), Syria conflict assessments, Q4 2025