The Counterterrorism 2025 Summit was convened on June 3rd through a collaborative partnership between GTSC’s Homeland Security Today and the Terrorism, Transnational Crime, and Corruption Center (TraCCC) at the Schar School of Policy and Government, George Mason University. The summit brought together a diverse array of participants, including representatives from government agencies, academia, the private sector, and think tanks, alongside prominent scholars in the field. The event provided a multidisciplinary platform for discussing critical and timely issues in counterterrorism.
The summit opened with a panel on global terrorism trends, featuring Ambassador Adam Blackwell, Director of the Global Terrorism Trends and Analysis Center (GTTAC), and Dr. Mahmut Cengiz, Academic Director of GTTAC and editorial board member of Homeland Security Today. This session offered a comprehensive overview of current global terrorism dynamics. Subsequent panels explored the continuing relevance of ISIS and al-Qaeda. Panelists reached a consensus on the enduring threat posed by both organizations and their affiliated networks. Another panel examined radicalization narratives, with particular attention to newly emerging themes in the aftermath of the Hamas attacks on October 7.
Further discussions addressed the evolving threat landscape associated with Iran-backed groups, such as Hezbollah and the Houthis, highlighting their growing operational capacity and the ongoing, destabilizing support provided by the Iranian regime. Afternoon sessions shifted focus to non-traditional threats, including cyberterrorism, and examined the implications of recent U.S. designations of Mexican cartels and transnational gangs as terrorist organizations. The summit concluded with panels on counterterrorism policy and the financing of terrorism. Panelists underscored the United States government’s sustained and strategic commitment to counterterrorism efforts, emphasizing the importance of adaptability and international cooperation in confronting the next generation of threats.
Ambassador Adam Blackwell and Dr. Mahmut Cengiz presented a detailed analysis of global terrorism trends using data compiled by GTTAC, which collects and analyzes terrorism-related data on behalf of the U.S. Department of State. Their initial analysis focused on the top 15 countries experiencing the highest number of terrorist incidents between 2018 and 2024. As illustrated in Figure 1 below, these 15 countries collectively accounted for approximately 83 percent of all recorded terrorist incidents globally during this period. Syria topped the list, followed by Afghanistan, which experienced nearly 2,000 attacks prior to the Taliban’s return to power in 2021. Following the takeover, the number of incidents in Afghanistan dropped to approximately 200, primarily attributed to ISIS-Khorasan.
Figure 1: Top 15 Countries with the Highest Number of Terrorist Attacks (2018–2024)
The Democratic Republic of the Congo (DRC) was responsible for 8.3 percent of the incidents, driven by violence perpetrated by groups such as CODECO, M23, ISIS-DRC, and various ethnically motivated militias. India accounted for 6.6 percent of global terrorist incidents, involving Naxalite insurgents in the central states, jihadist actors in Jammu and Kashmir, and ethnonationalist movements in the northeastern regions. Nigeria followed closely, with 5.8 percent of incidents linked to Boko Haram, ISIS-West Africa Province (ISWAP), and other ethnic armed groups. Iraq was also among the top countries, contributing 4.8 percent of the global total. Although ISIS activity in Iraq has declined, Iran-backed militia groups continue to pose a growing threat to the country’s stability.
Israel recorded 4.8 percent of global attacks, the majority of which occurred after the October 7, 2023, terrorist attacks and were attributed to Hezbollah, Hamas, and Palestinian Islamic Jihad (PIJ). Yemen also featured on the list, with most incidents carried out by the Houthis—recently designated as a terrorist group—and by al-Qaeda in the Arabian Peninsula (AQAP). The Sahel countries of Mali and Burkina Faso recorded high levels of violence, primarily driven by Jama’at Nasr al-Islam wal Muslimin (JNIM) and ISIS in the Greater Sahara. In particular, post-coup instability in Mali, Burkina Faso, and Niger has created power vacuums that JNIM has rapidly exploited. Colombia rounded out the list, accounting for 2.2 percent of global terrorist incidents. Although the 2016 peace agreement with FARC reduced overall violence, attacks have persisted due to continued activity by the National Liberation Army (ELN) and dissident factions of FARC.
Syria holds a distinctive position in the analysis of global terrorism trends, having consistently ranked among the countries with the highest number of terrorist incidents. Between 2018 and 2024, the country recorded between 800 and 1,200 attacks annually, as shown in Figure 2 below. The takeover by Hay’at Tahrir al-Sham (HTS) in December 2024 has raised critical questions regarding how this shift in control might influence the nature and frequency of terrorist activity in the region. Preliminary data from the first five months of 2025, compiled by GTTAC, suggest that ISIS is likely to maintain a pattern of low-profile, decentralized attacks. Additionally, there are emerging indications that segments of the Alawite community may begin organizing resistance movements aimed at undermining the HTS-led administration, potentially adding a new layer of sectarian and political violence to the already complex security landscape in Syria.
Figure 2: Recorded Terrorist Incidents in Syria, 2018–2024
Another country that warrants special attention in the analysis of global terrorism trends is Pakistan. From 2018 until the Taliban’s takeover of Afghanistan in 2021, Pakistan consistently recorded approximately 300 terrorist incidents annually. However, the post-takeover period has seen a significant escalation in violence, highlighting the unintended consequences of Pakistan’s historical support for the Taliban. Following the regime change in Kabul, Pakistan experienced a sharp increase in attacks, particularly by Tehrik-e-Taliban Pakistan (TTP) in the Khyber Pakhtunkhwa region, as well as by various separatist and insurgent groups in Baluchistan. This surge in violence reflects the growing security challenges posed by both transnational militant spillover and long-standing internal political tensions, complicating Pakistan’s domestic counterterrorism efforts and regional stability.
Figure 3: Annual Terrorist Attacks in Pakistan, 2018–2024
The monthly breakdown of terrorist attacks from 2018 to 2024 provides another critical dimension in understanding global terrorism trends, as illustrated in Figure 4 below. The data reveal a clear seasonal pattern, indicating that terrorist groups tend to escalate their operations during the spring and summer months. In particular, March, May, and June consistently recorded the highest number of attacks and fatalities. Across these three months, terrorist incidents collectively resulted in the deaths of approximately 17,000 individuals. This seasonal concentration suggests that militant organizations may be taking advantage of favorable weather conditions, logistical ease, and potential symbolic timing to maximize operational impact and visibility.
Figure 4: Monthly Breakdown of Casualties Resulting from Terrorist Attacks, 2018–2024
Figure 5 below presents the distribution of weapon types used in terrorist attacks from 2018 to 2024. Firearms were the most commonly used weapon, accounting for approximately 40 percent of attacks annually. Explosives followed closely, with a notable spike in 2024, largely attributed to the increased activity of Iran-backed terrorist groups following the October 7 attacks. Improvised Explosive Devices (IEDs) were employed in roughly 10 percent of incidents, reflecting their continued relevance as a low-cost, high-impact tactic among various militant organizations. Additionally, the growing use of unmanned aerial vehicles (UAVs)—particularly evident in 2024—marks a striking development, signaling an evolution in terrorist tactics and the increasing adoption of technologically sophisticated methods.
Figure 5: Percentage Distribution of Weapon Types Used in Terrorist Attacks (2018–2024)
According to Figure 6 below, shooting emerged as the most commonly employed tactic by terrorist groups, accounting for 44.8 percent of all recorded attacks. This was followed by bombings, which comprised 24.2 percent of incidents. Other frequently used methods included the planting of IEDs and landmines, both of which remain prevalent due to their accessibility and effectiveness. Additional tactics observed included kidnappings, ambushes, suicide bombings, and targeted assassinations, reflecting the diverse operational strategies adopted by various terrorist organizations. In the context of lone-actor terrorism, car ramming and stabbing were identified as the two most common forms of attack, underscoring the persistent threat posed by individuals acting independently, often with minimal resources but significant impact.
Figure 6: Percentage Distribution of Common Terrorist Tactics (2018–2024)
Terrorist organizations often claim responsibility for attacks as a strategic means of gaining visibility and asserting their presence. Despite the risk of punitive consequences following such acts, these groups understand that claiming responsibility can enhance their popularity, which in turn contributes to increased recruitment and funding. As illustrated in Figure 7, the number of attacks where perpetrators publicly claimed responsibility has shown a marked increase over time. Notably, the sharp rise in 2023 and 2024 is closely linked to the October 7 attacks, after which Iran-backed terrorist groups escalated their operations and actively claimed responsibility, as further detailed in Figure 8. This trend highlights the deliberate use of public attribution by militant organizations as a tool for propaganda, legitimacy, and strategic communication.
Figure 7: Terrorist Attacks with Claimed Responsibility, 2018–2024
Figure 8 below shows a marked increase in terrorist attacksby Iran-backed groups, primarily carried out by Hezbollah, the Houthis, Hamas, and the Islamic Resistance in Iraq. These groups have maintained significant operational capacity amid rising regional tensions, reflecting their strategic aims and responses to recent events such as the October 7 attacks. This trend highlights the ongoing threat posed by state-backed and proxy militant organizations in the Middle East.
Figure 8: Terrorist Attacks by Iran-Backed Groups, 2018–2024
Although ISIS and its affiliated groups have been largely contained within their traditional operational theaters, data from GTTAC indicate a concerning persistence and expansion of their activities, as illustrated in Figure 9 below. Notably, ISIS-Core alone was responsible for more than 4,000 attacks during the analyzed period. Additionally, its regional affiliates continue to conduct significant operations in diverse locations, including the Democratic Republic of Congo, Mozambique, Nigeria, the Sahel countries, and Afghanistan. This sustained activity underscores the adaptability and resilience of ISIS’s network despite concerted counterterrorism efforts.
Figure 9: Terrorist Attacks by ISIS and Its Affiliates, 2018–2024
A critical trend in African terrorism is the persistent and expanding activity of Al-Qaeda-affiliated groups. Figure 10 below highlights the sustained resilience of Al-Shabaab and the marked increase in attacks by JNIM throughout the Sahel region. Notably, JNIM has alarmingly extended its operational capacity from Mali into neighboring countries, including Burkina Faso, Niger, Togo, and Benin. This expansion underscores the growing influence and geographical spread of Al-Qaeda’s network in West Africa.
Figure 10: Terrorist Attacks by Al-Shabaab and JNIM, 2018–2024
In conclusion, terrorism continues to represent a significant and escalating threat within the global security environment. The trends presented at the Counterterrorism 2025 Summit highlight an increasing frequency of terrorist attacks concentrated in conflict zones, coupled with the intensified activities of Iran-backed groups in the aftermath of the October 7 attacks. Additionally, these organizations have enhanced their operational capabilities, notably through the expanded use of explosives and unmanned aerial systems. These developments underscore the evolving complexity of the terrorist threat and the imperative for comprehensive, adaptive, and coordinated counterterrorism responses. Looking ahead, the Counterterrorism 2026 Summit will continue to provide critical insights into these evolving dynamics, drawing on robust data and analysis from GTTAC.
