Ideological Trends in U.S. Terrorism

The Warfare, Irregular Threats, and Terrorism Program examines the state of terrorism in the U.S., finding left-wing violence has risen in the last decade but from very low levels and still well below historic levels of violence by right-wing and jihadist actors. 

1. The number of left-wing terrorism incidents has risen in the last 10 years, though from very low levels, and remains much lower than historical levels of violence carried out by right-wing and jihadist attackers. The increase is largely driven by plots and attacks directed at government and law enforcement targets. In 2025, opposition to the Trump administration has fueled attacks on both its political leadership and the state institutions implementing its agenda. Despite the rise in the number of left-wing incidents, the overall lethality of left-wing attacks remains very low.
2. Left-wing attacks and plots as a share of all terrorist attacks and plots reached a record high in the first half of 2025, although the decline of other forms of terrorism plays a significant role in this relative increase. The decline of right-wing terrorism in 2025 is striking, and explanations are speculative. One possibility is that many traditional grievances of violent right-wing extremists have espoused in the past—opposition to abortion, hostility to immigration, and suspicions of government agencies, among others—are now embraced by President Trump and his administration. Jihadist attacks have also declined in frequency since their peak in the 2010s, owing largely to the destruction of major groups like al-Qaeda and the Islamic State and the subsequent decline in the power of the jihadist ideology as a driver of violence.
3. The rise in left-wing attacks warrants increased attention, but the fall in right-wing violence is likely temporary and requires a government response as well. Many of the measures needed for fighting terrorism effectively apply to violence from both the left and right. These include ensuring proper counterterrorism resourcing, avoiding overreactions, and having leadership unequivocally condemn such attacks.