Why Didn’t Iran Use Terrorism?

This commentary was originally published in a Blue Blaze Substack post on April 12, 2026.

The United States has long described Iran as “the leading state sponsor of terrorism,” using both the Islamic Revolutionary Guard Corps (IRGC, the rare state entity the United States has designated as a terrorist group) and an array of terrorist groups, such as the Lebanese Hezbollah, Hamas, and the Houthis in Yemen, as proxies. Iran and Iranian-backed proxies have conducted or attempted attacks in Argentina, Bahrain, Bosnia, Bulgaria, Germany, Kenya, Saudi Arabia, Turkey, the United States, and other countries. This history spans decades and includes both spectacular international attacks and more limited operations designed to signal resolve without triggering full-scale war.

Given this track record, it would be reasonable to think that Iran would use terrorism in its 2026 war with Israel and the United States, both of which declared “regime change” as one of their goals—a truly existential threat to Iran’s leaders. Yet, so far at least, Iran has not used terrorism even though it has launched rocket, missile, and drone attacks on civilian as well as military targets in the region and closed the Strait of Hormuz.

What explains this surprising lack of terrorism? It’s difficult to know why something didn’thappen, but here I offer four nonexclusive possibilities. Each points to a different constraint on Iranian decisionmaking, ranging from operational limits to strategic restraint.

Perhaps the simplest explanation is the best: Iran did not conduct terrorist attacks on the United States and its allies because it was not able to do so. The Israeli and U.S. attacks on Iran, especially the assassination campaign that killed over 250 senior Iranian political and military leaders, demonstrated a remarkable intelligence penetration of Iran. Although the intelligence required to target leaders differs from that necessary to disrupt operations, it is plausible that some of the techniques that led to the assassinations also revealed information on terrorist operations, allowing for disruption. Equally important, Iran itself was probably running scared, believing that its operations and networks might be penetrated even if they were not. It is also likely that the assassination campaign disrupted command and control, making it difficult to organize and direct operations while also hiding from U.S. and Israeli airstrikes. In this sense, the absence of terrorism may reflect not restraint but temporary incapacity—an intelligence-driven suppression of Iran’s external networks at a critical moment.

A second possibility is that Iran feared escalation and retaliation from the United States and Israel. That may seem an odd fear given the firepower unleashed in Operations Epic Fury and Lion’s Roar (the Israeli equivalent). The United States, however, could easily have inflicted more damage on Iran. Trump was already promising to unleash destruction on a “whole civilization” and target power plants and bridges, and the United States was also sending ground forces to the Gulf region. Terrorism, particularly against the U.S. homeland or high-profile civilian targets, risked transforming a limited war into a far broader and more existential conflict for the Iranian regime.

A related third possibility is the risk of blowback for Iran. The Iran war was unpopular in the United States, but a terrorist attack could bolster support, creating a casus belliwhere one was previously lacking. The conflict was even less popular in Europe and Asia, but terrorist attacks there might increase hostility toward Iran and thus support for U.S. and Israeli attacks. Rather than dividing Iran’s adversaries, terrorism might unify them—strengthening political will, legitimizing escalation, and undermining Tehran’s efforts to portray itself as a victim of aggression.

The fourth possibility is the most grim—that such attacks are in the pipeline but just haven’t happened yet. Revenge, like ice cream, is best served cold. Iran waited over a year to begin a plot to kill former National Security Adviser John Bolton because of his role in the U.S. assassination of IRGC Quds Force leader Qasem Soleimani. That U.S. violence pales by comparison to the scale of the 2026 killings, including the assassination of Iran’s supreme leader, intelligence chief, head of the IRGC, and many others. Iran may simply be looking for the right opportunity to exact revenge, perhaps waiting until the conflict is completely over and the risk of escalation is lower.

A fifth possibility is that Iranian leaders believe that they do not need to use terrorism because their current response has succeeded. Drone strikes, missile attacks, shipping disruption, and proxy warfare have already allowed Tehran to impose costs and create an effective deterrent for the resumption of the war. In this context, terrorism may have been redundant—offering limited additional leverage while carrying disproportionate risks.

Taken together, these explanations suggest that Iran’s restraint is contingent rather than permanent. Whether due to capability constraints, strategic caution, or timing, the underlying logic that has long driven Iran’s use of terrorism may simply be dormant—for now.

Daniel Byman is the director of the Warfare, Irregular Threats, and Terrorism Program at the Center for Strategic and International Studies in Washington, D.C.