The U.S. Anti-ISIS Coalition and Syrian Democratic Forces (SDF) began operations to clear ISIS from Ar-Raqqa City in Northern Syria on June 6. This urban combat phase marks the culmination of successful shaping operations conducted over the last eight months to isolate Ar-Raqqa City under Operation Euphrates Wrath. These operations included the seizure of the Tabqa Dam in Western Ar-Raqqa Province on May 10. Ar-Raqqa City is currently isolated along its three axes with only limited water traffic to the south across the Euphrates River. The fight for the city will nonetheless prove difficult. ISIS retains at least 2,500 fighters in the city behind an elaborate system of berms, tunnels, improvised explosive devices, and other defenses “very similar” to its posture in Mosul, Iraq. ISIS’s forces are intermingled with an estimated50,000 to 100,000 civilians, raising the complexity and requirements of ongoing clearing operations. ISIS has thus far mounted a kinetic defense, ceding some outlying districts in favor of raids, ambushes, sleeper cells, and suicide attacks as the group falls back towards the dense urban core of Ar-Raqqa City. The capability of the SDF – a coalition of irregular forces dominated by the Syrian Kurdish YPG – to sustain its offensive and overcome these challenges remains doubtful despite expansive support from the U.S. Anti-ISIS Coalition.
The campaign for Ar-Raqqa City also faces significant challenges beyond the urban fight. Continued U.S. support to the YPG risks alienating local Sunni Arabs whose support will be required to secure and govern the city over the long term against the threat posed by ISIS, Al-Qaeda, and other Salafi-Jihadist groups. The local population’s long-standing ethnic and political grievances will not be addressed by the participation of Sunni Arabs in the Syrian Arab Coalition (SAC) or Raqqa Civilian Council – both of which locals view as mere puppets of the YPG in Northern Syria. The decision to back the YPG in Ar-Raqqa City also furthers a widening divide between the U.S. and Turkey in Syria. Turkey views with deep suspicion the institutional links between the YPG and the Kurdistan Workers’ Party (PKK), a designated Foreign Terrorist Organization that is currently waging an active insurgency in Southern Turkey. Turkish President Recep Erdogan mounted a failed lobbying campaign to convince both U.S. President Donald Trump and former U.S. President Barack Obama to halt their support for the SDF in Northern Syria in favor of opposition groups backed by Turkey. Turkey retains the capability to launch a major cross-border intervention against the YPG along the Syrian-Turkish Border - particularly at the border town of Tel Abyad in Northern Ar-Raqqa Province. Turkey nonetheless will likely eschew any intervention over the near term and instead hope that the YPG weakens itself through a sustained engagement in Ar-Raqqa City. The Russo-Iranian Coalition also remains poised to exploit any setbacks suffered by the SDF in Ar-Raqqa City. Forces loyal to Syrian President Bashar al-Assad advanced into regions directly abutting the SDF in Tabqa in Western Ar-Raqqa Province on June 13. The U.S. later shot down a Syrian Arab Air Force fighter jet after the aircraft dropped munitions near positions held by the SDF near Tabqa on June 18. Russia, Iran, and Assad likely intend to block further gains by the SDF near Ar-Raqqa City as part of a wider effort to constrain the U.S. Anti-ISIS Coalition in Eastern Syria that began in May 2017.