Analysis on Situations in Syria and Lebanon

 Key Judgements

• Syria’s interim government faces a critical December 31, 2025, deadline to integrate Kurdish SDF forces, threatening the fragile one-year-old political transition if negotiations fail.

• Lebanon’s inability to disarm Hezbollah by the US-imposed December 31 deadline risks triggering renewed military conflict, with Israel conducting 5,350 ceasefire violations since November 2024.

• The parallel December deadlines in Syria and Lebanon create compounding regional instability, while Iraq’sUNAMI withdrawal and continued Houthi Red Sea attacks further strain security coordination across the MENA region.

Objective

This report examines how Syria’s political transition and Lebanon’s Hezbollah disarmament crisis, both facing end-of-year deadlines, are creating a critical juncture for regional stability, with spillover effects across Iraq, Yemen, and Red Sea security.

Context

December 8, 2025, marked one year since Bashar al-Assad’s regime fell, when Hay’at Tahrir al-Sham (HTS) led forces seized Damascus, and Assad fled to Russia. Interim President Ahmed al-Sharaa’s transitional government has since restructured governance, consolidated armed forces, and pursued international reintegration.However, critical challenges remain: integrating the Kurdish-led Syrian Democratic Forces (SDF) by year-end per a March 10 agreement, managing ethnic tensions, and rebuilding after 13 years of civil war.

Simultaneously, Lebanon faces intense pressure to disarm Hezbollah by December 31 under a US-brokered 2024 ceasefire agreement. The ceasefire has proven one-sided; Hezbollah is prohibited from firing “even a single bullet” while Israel conducts preemptive strikes at will. Lebanese authorities report 5,350 violations since the November 27, 2024, ceasefire began, including 2,983 airstrikes, resulting in 331 deaths and 945 injuries. Israel launched intense airstrikes across southern and northeastern Lebanon on December 18 as the deadline approached.

Timeline

• December 8, 2024: Assad regime falls; HTS assumes power in Damascus
• November 27, 2024: US-brokered Israel-Hezbollah ceasefire takes effect
• March 10, 2025: Syria-SDF integration agreement signed with a December 2025 deadline
• November 26, 2025: US sets December 31 deadline for Hezbollah disarmament
• December 8, 2025: Syria celebrates first anniversary of Assad’s fall
• December 18, 2025: Israeli airstrikes intensify across Lebanon; Syria-SDF negotiations continue
• December 31, 2025: Dual deadlines; SDF integration and Hezbollah disarmament; UNAMI exits Iraq

Analysis

 Regional Security Implications

Syria’s transition faces its most critical test as SDF integration negotiations race against the December 31 deadline.Despite Commander Mazloum Abdi’s November 11 commitment to “accelerate integration,” deadly clashes continued in Raqqa and Deir Ezzor governorates through late November. Failure to integrate the SDF, a key US partner controlling Syria’s autonomous northeast, risks fracturing Syria’s territorial integrity and complicating counter-ISIS operations along the Syrian-Iraqi border.

The Lebanon crisis presents even greater escalation risks. Hezbollah lawmaker Ali Ammar explicitly rejected disarmament, stating the group’s arsenal “will remain” until Israel withdraws from border positions and releases Lebanese detainees. Israeli Defense Minister Israel Katz warned military action may be the “only remaining option,” acknowledgingdiplomatic channels have stalled with “no real indication” of compliance. This creates immediate potential for renewed conflict that could destabilize Lebanon’s newly formed government under Prime Minister Nawaf Salam and President Joseph Aoun.

Broader Regional Patterns

These crises unfold amid a deteriorating regional security architecture. Iraq’s security landscape remains volatile as UNAMI concludes its drawdown by December 31, removing international monitoring capacity precisely when regional tensions peak. ISIS continues exploiting Syria’s transition, focusing on rebuilding networks along the Syrian-Iraqi border and the Badia region.

Meanwhile, Houthi forces maintain pressure on Red Sea commercial shipping, launching missiles and drones at vessels as recently as December 5.

The convergence of these developments threatens coordinated counterterrorism efforts across the region. Syria’s potential fragmentation, Lebanon’s instability, Iraq’s reduced international presence, and continued Houthi operations create opportunities for ISIS and other extremist groups to exploit governance vacuums.

Outlook and Risks

The next two weeks are critical. If Syria’s SDF integration fails, ethnic violence could erupt in northeastern Syria, complicating reconstruction and refugee return. Missing the Hezbollah

deadline risks triggering what Washington warns could be a “new military conflict” with Lebanon bearing “fullresponsibility”. Such escalation would likely draw in regional actors and further destabilize an already fragile transition period across multiple MENA states.