From the areas that Islamic State continues to control in the eastern province of Deir Ez Zor, Islamic State has managed to increasingly expand its activities against the Syrian government to Homs, as well as Hama and Raqqa.¹See ‘Key developments’

In 2024, ambushes against the former Syrian government gained in regularity, some demonstrating a high level of coordination and using heavy weaponry, including missiles and light rockets. These incidents have led to significant casualties among the Syrian armed forces, their facilities, as well as harm to civilians and their livelihoods.²Gregory Waters, ISIS Insurgency, Syria, 15 October 2024 More recently, Islamic State has demonstrated that it retains its operational capacity, also in light of the interim government’s efforts to defeat Islamic State’s presence. On 18 May 2025, for instance, Islamic State killed or wounded five Syrian soldiers through the use of an explosive device in the eastern town of Mayadin.³A. Y. Zelin, The Islamic State Attacks the New Syrian Government, The Washington Institute, 19 May 2025. Similarly, on 22 June 2025, Islamic State’s suicide bomb attack on a church in Damascus killed at least 22 individuals and wounded 63 others.⁴Christou, Islamic State suicide bombing in Damascus church kills 22 and injures 63, The Guardian, 22 June 2025.

Hence, the frequency, organization, and sophistication of the attacks involving Islamic State and the Syrian government remain sufficient to satisfy the intensity threshold under IHL. Given that Islamic State fulfils the organization criterion,⁵See ‘Armed conflicts in Iraq it can be concluded that a NIAC between the Syrian government and Islamic State is ongoing. ⁶See UNSC, Twentieth report of the Secretary-General on the threat posed by Islamic State (Da’esh) to international peace and security and the range of United Nations efforts in support of Member States in countering the threat, UN Doc S/2025/72, 31 January 2025, para 6; Masood Al Hakari, Without a Caliphate, But Far from Defeated: Why Da’esh/ISIS Remains a Threat in Syria in 2025, PRIF Blog, 7 April 2025. Although evidence suggests that Islamic State continues to exercise control over certain parts of the territory such as to carry out sustained and concerted military operations, Syria is not a party to Additional Protocol II of 1977 and that treaty is not applicable.

• 1
  See ‘Key developments’ ↩︎
• 2
  Gregory Waters, ISIS Insurgency, Syria, 15 October 2024 ↩︎
• 3
  A. Y. Zelin, The Islamic State Attacks the New Syrian Government, The Washington Institute, 19 May 2025. ↩︎
• 4
  Christou, Islamic State suicide bombing in Damascus church kills 22 and injures 63, The Guardian, 22 June 2025. ↩︎
• 5
  See ‘Armed conflicts in Iraq it can be concluded that a NIAC between the Syrian government and Islamic State is ongoing. ↩︎
• 6
  See UNSC, Twentieth report of the Secretary-General on the threat posed by Islamic State (Da’esh) to international peace and security and the range of United Nations efforts in support of Member States in countering the threat, UN Doc S/2025/72, 31 January 2025, para 6; Masood Al Hakari, Without a Caliphate, But Far from Defeated: Why Da’esh/ISIS Remains a Threat in Syria in 2025, PRIF Blog, 7 April 2025. ↩︎