ISIS Recaptures Palmyra in Major Blow to Pro-Regime Forces

ISIS recaptured the historic city of Palmyra in Eastern Homs Province on December 11 following the withdrawal of pro-regime forces, marking the first seizure of a major urban center by ISIS in Iraq and Syria since ISIS last captured Palmyra in May 2015. ISIS launched a multi-axis offensive against the outskirts of Palmyra beginning on December 8, 2016, seizing several nearby regime-held oil and natural gas fields as well as critical positions in the mountains overlooking the city. Local activists stated that Russia and Iran withdrew their garrisons from Palmyra as this outer line of defenses began to collapse, leaving the city under the control of only several hundred ill-trained and poorly-motivated militiamen from the National Defense Forces. These fighters proved unable to hold the city despite heavy air support provided by Russia. ISIS subsequently capitalized upon its advances to launch an attack against the T4 (Tiyas) Airbase between Palmyra and Homs City. Heavy clashes reportedly remain ongoing as of December 13.

The fall of Palmyra demonstrates ISIS’s sustained ability to command, control, and resource major operations even as it mounts the defense of Mosul in Iraq and Ar-Raqqa City in Syria. ISIS exploited the ongoing main effort of pro-regime forces in Aleppo City in order to recapture Palmyra with an offensive maneuver characteristic of its previous campaigns, allowing ISIS to shift the pervading narrative that it is on its heels in Iraq and Syria. Palmyra is key terrain that positions ISIS to project force into regime-held ‘central corridor’ of Western Syria, including Damascus, Homs City, and Hama City. ISIS may continue its offensive south and west of Palmyra in Central Syria in order to maximize its gains as ongoing offensives against Al-Bab in Northern Aleppo Province and Ar-Raqqa City challenge its urban holdings in Northern Syria. Notably, ISIS claimed to replenish its arsenal with dozens of armored vehicles, anti-tank missiles, and other systems left behind by pro-regime forces in Palmyra. The seizure of Palmyra by ISIS may also be a blocking maneuver to protect its holdings in Eastern Syria or a diversionary effort to set conditions for a renewed offensive against pro-regime positons in Deir ez-Zour City. In either case, ISIS will likely use its offensives against the regime in order to expand its influence, leverage, and recruitment among the opposition following the upcoming fall of Eastern Aleppo City.

The success enjoyed by ISIS in Palmyra also highlights the fragility of pro-regime forces despite their recent gains in Western Syria, foreshadowing the difficulty that the regime and its allies will face in securing the country over the long-term. Syrian President Bashar al-Assad remains reliant upon a small cadre of elite military units and foreign fighters – including Russian Spetznaz, Lebanese Hezbollah, and Iraqi Shia Militias – in order to secure gains against his opponents on the ground. The regime reportedly redeployed the majority of these assets to enable its successful operations to clear opposition forces from Eastern Aleppo City over the past several months, generating vulnerabilities on other battlefronts including Central Syria. Pro-regime forces remain unlikely to deploy in large numbers to Eastern Homs Province in the near-term. Russia will likely use this renewed threat in order to press the U.S. for increased cooperation against ISIS in Syria. Nonetheless, the regime remains incapable of reestablishing security across the country without sustained foreign support – and thus remains incapable of meeting the long-term strategic objectives of the U.S. in Syria.