international volunteers in the Spanish Civil War and citizens of some Arab states, including Osama bin Laden, who fought in the Soviet–Afghan War. Denaturalization on this basis expanded during the early twenty-first century due to increasing terrorist attacks in Europe and the phenomenon of people traveling to the Middle East to fight for the Islamic State group. Justifications for denaturalization and denial of return include national security and the belief that joining a terrorist group is an act of disloyalty that merits denaturalization. In some countries, denaturalization can take place only after a conviction for a terrorism-related crime; in other jurisdictions, a conviction is not required and few individuals denaturalized have been convicted of a crime. In the scholarly literature, it is disputed that denaturalization is an effective counterterrorism tactic. Critics argue that it can lead to additional marginalization and further radicalization of the affected individual or their community. According to counterterrorism researcher David Malet, "Osama Bin Laden is Exhibit A of the folly of stripping a foreign fighter’s citizenship and then washing your hands and assuming the individual is no longer your problem." Another consequence of denaturalization is worsening relations with third countries who view it as an illegitimate attempt to export terrorism risks. In Iraq, suspected Islamic State militants (including foreign fighters) are often subjected to ten-minute trials that often result in the death penalty. Turkey has rejected hosting foreign fighters denaturalized by European countries, and managed to deport denaturalized Europeans back to their countries of origin. In 2019, US Department of Homeland Security has employed the software ATLAS, which run on Amazon Cloud. It scanned more than 16.5 million of records of naturalized Americans and flagged approximately 124.000 of them for manual analysis and review by USCIS officers regarding denaturalization. Some of the scanned data came from Terrorist Screening Database and National Crime Information Center. The algorithm and the criteria for the algorithm were secret. This information was revealed through efforts of Open Society Justice Initiative and Muslim Advocates, a sister organization of National Association of Muslim Lawyers. Fraudulent naturalization Many countries allow denaturalization in cases where an applicant for citizenship committed fraud during the naturalization process. According to legal scholar Audrey Macklin, "The logic of citizenship revocation for fraud or misrepresentation is that it unwinds the effect of the misleading conduct and restores the situation that would have been obtained had the truth been disclosed." Denaturalization