(TLP:CLEAR) Center for Strategic and International Studies – Global Terrorism Threat Assessment 2026

Summary: The Center for Strategic and International Studies (CSIS), a Washington-based think tank, published its annual report analyzing the terrorist threat landscape around the world. The report, “Global Terrorism Threat Assessment 2026,” warns that the U.S. faces an increasingly complex and unpredictable terrorism landscape.

Analyst Note: Following the start of U.S. military action in Iran on February 28, there have been at least four violent extremist attacks within the U.S., underscoring the dynamic terrorist threat landscape facing the U.S. homeland. The report asserts that the U.S. faces a variety of formal groups, loose networks, and lone actors who intend to kill Americans and spread fear in the U.S. or otherwise threaten important U.S. security interests. Still, terrorist attacks in the U.S. remain less prevalent than in other regions, but the incidents and fatalities recorded by CSIS increased in 2025 to 40 attacks and 31 deaths.

In terms of ideology, anti-government extremism is the most common motivation, driven largely by a growth in left-wing incidents targeting immigration enforcement authorities. These actors previously focused on property destruction compared to targeted attacks. “Partisan extremism, including the threat of politically motivated assassinations, will likely remain a feature of U.S. politics, with the 2026 midterm cycle likely to intensify that threat,” according to the report. Although Islamist-inspired attacks remain relatively infrequent in the U.S., they can result in significant casualties, as illustrated by the Bourbon Street attack in New Orleans on New Year’s Day 2025, which claimed 14 lives. Relatedly, the ongoing U.S. and Israeli war with Iran has increased Iran’s incentives to conduct terrorist attacks against the U.S. and its allies. White supremacist terrorism has killed fewer people in the short term. However, it remains a potent threat.

In the Middle East and Africa, according to the report, “al Qaeda affiliates and Islamic State provinces pose the greatest threat. Many formal groups, especially those in Africa, are growing in strength. Even if they do not currently intend to attack the U.S. homeland, there is little guarantee that their intentions will remain the same in the next few years.” Lastly, the report finds that terrorist groups are making increasing use of unmanned aerial systems (UASs) and artificial intelligence.

Original Source: https://www.csis.org/analysis/global-terrorism-threat-assessment-2026

Additional Reading:

• Global Terrorism Index

Mitigation Recommendations:

• US Violent Extremist Mobilization Indicators 2021 Edition
• CISA – Personal Security Considerations Action Guide
• FBI Guidance on Keeping Potential Attackers off the ‘Pathway to Violence’

Related WaterISAC PIRs: 1 & 2