Foreign terrorist fighters (FTFs) travel to conflict zones to engage in terrorist acts. The persuasive use of propaganda by Islamic State of Iraq and the Levant (ISIL) led to an unprecedented flow of volunteers from countries around the world to live under the rule of the terrorist group. This included not only men, but also women alone and families.

In 2015, approximately 40,000 individuals from over 120 countries had travelled to Iraq and the Syrian Arab Republic as fighters. An estimated 80 per cent of those migrated to join ISIL (Da’esh) and live in the caliphate, creating a combined force with local Syrians and Iraqis assessed at around 100,000 fighters.

Since 2017, ISIL has lost most of the territory it occupied in Iraq and Syria in preceding years and many FTFs have returned, or attempted to return, to their countries of origin. Also returning foreign terrorist fighters pose a significant threat to peace and security. A likely outcome of not pursuing repatriation and prosecution is that these fighters re-engage in terrorism, which may go undetected in the countries where they relocate.


By September 2014, a pattern of individuals travelling abroad to join terrorist entities including ISIL, al-Nusrah Front and entities associated with Al-Qaida, had grown into such a concern that the Security Council adopted resolution 2178 (2014). The resolution specifically called upon Member States to enhance their criminal justice responses to FTFs by introducing measures to detect, prevent and criminalize the travel of FTFs and related activities.

In December 2017, the Security Council unanimously adopted resolution 2396 (2017). The resolution addresses the risks posed by FTFs returning from conflict zones. It calls upon Member States to strengthen their efforts to stem the threat emanating from returning and relocating FTFs and their family members, including women and children, through measures on border control, criminal justice, and information-sharing.


Since 2014, we have been supporting Member States with their responses to Foreign Terrorist Fighters under the umbrella of the Global Project on Strengthening the Legal Regime against Foreign Terrorist Fighters in the Middle East, North Africa and South Eastern Europe. The assistance provided focused on enhanced legal frameworks, the use of information as admissible evidence, special investigation techniques, countering terrorism financing, and international cooperation.

UNODC has also provided support to Lebanon with criminal justice measures against the potential recruitment and infiltration of terrorist militants among the refugee population. We supported authorities’ efforts to detect, intercept and monitor terrorism-related activities in refugee-centred areas. The assistance provided allowed security and judicial authorities to analyse operational challenges posed by different cases involving FTFs, share good practices and databases, and discuss ongoing investigations and cases.

Recent activities

March 2021
UNODC conducted a regional event which officially concluded its five-year project on Strengthening the Legal Regime against FTFs in the Middle East, North Africa and South-Eastern Europe (2015-2021), funded by the European Union.

December 2020
UNODC delivered two workshops for Lebanon on crime scene investigation management and digital evidence in terrorism-related cases.

November 2020
UNODC delivered two training sessions for Jordanian and Lebanese law enforcement and criminal justice officials on investigative interviewing in terrorism-related cases.


Our work on responses related to foreign terrorist fighters has been funded by the European Union, Germany and the United States.