Why didn’t Iran carry out terrorist attacks during the war? Expert responds

The United States has long described Iran as “the leading state sponsor of terrorism,” going so far as to designate the Islamic Revolutionary Guard Corps (IRGC) as a terrorist group. And the ayatollah regime supports and finances armed groups like Hezbollah, Hamas and the Houthis in Yemen. Therefore, an important question has been asked even by geopolitical experts: why didn’t Iran retaliate for the attacks on the country with terrorist actions?

For Daniel Byman, director of the War, Irregular Threats and Terrorism Program at the Center for Strategic and International Studies (CSIS), this is a question that can have different answers.

He recalls that the Tehran regime and its “proxies” conducted or attempted to conduct attacks in countries as different as Argentina, Bahrain, Bosnia, Bulgaria, Germany, Kenya, Saudi Arabia, Turkey and the United States, among others.

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This history, the expert comments, spans decades and includes both spectacular international attacks and more limited operations designed to signal determination without triggering a 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 have declared ‘regime change’ as one of their goals,” Byman writes. However, so far at least, Iran has not resorted to terrorism, although it has launched rocket, missile and drone attacks against civilian and military targets in the region and has closed the Strait of Hormuz.

The director of the think tank lists a series of possible explanations for this surprising absence of terrorism. Each points to a different constraint on Iranian decision-making, ranging from operational limits to strategic containment:

1 – Temporary incapacity

This is the simplest explanation and perhaps the one that best reflects the current situation, says Byman. In other words, Iran did not carry out terrorist attacks against the United States and its allies simply because it was unable to do so. He comments that the Israeli and American attacks on Iran, especially the assassination campaign that killed more than 250 important Iranian political and military leaders, demonstrated a remarkable intelligence penetration in the country.

“Although the intelligence needed to target leaders is different from that needed to disrupt operations, it is plausible that some of the techniques that led to the assassinations also revealed information about terrorist operations, allowing them to be interrupted,” he explains.

He adds that it is also likely that the assassination campaign undermined command and control, making it difficult to organize and direct operations at the same time that leaders needed to hide from US and Israeli airstrikes. “In this sense, the absence of terrorism may reflect not containment but temporary incapacitation — an intelligence-based suppression of Iran’s external networks at a critical time.”

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2 – Fear of escalation

The second possibility raised is that Iran feared even stronger escalation and retaliation from the United States and Israel. This may seem like a strange fear, given the firepower unleashed in Operations Epic Fury and Lion’s Roar (the Israeli equivalent). The United States, however, could easily have inflicted even more damage on Iran. Donald Trump has already promised to unleash destruction on “an entire civilization” and attack power plants and bridges, and the United States was also sending ground forces to the Gulf region.

“Terrorism, particularly against the U.S. mainland or high-profile civilian targets, risked turning a limited war into a much broader and more existential conflict for the Iranian regime,” argues Byman.

3 – Loss of international support

The third possibility discussed is the risk of an adverse international reaction to Iran. The war against Iran does not have great popular support in the United States, but a terrorist attack could increase its approval, creating a motivation (“casus belli”) that was previously weak or non-existent.

The conflict is even less popular in Europe and Asia, but the expert warns that terrorist attacks on the European continent could increase hostility towards Iran and, thus, increase the number of supporters of the North American and Israeli attacks. “Rather than dividing Iran’s adversaries, terrorism could unite them — strengthening political will, legitimizing escalation, and undermining Tehran’s efforts to present itself as a victim of aggression.”

4 – Wait for opportunity

The fourth possibility is considered by Byman to be the darkest: terrorist attacks are already in preparation. “Revenge, like ice cream, is best served cold. Iran waited more than a year to start plotting the assassination of former National Security Advisor John Bolton, because of his role in the US killing of the leader of the IRGC Quds Force, Qasem Soleimani”, recalls the director of the think tank.

This American violence pales in comparison to the scale of the killings in 2026, including the assassination of Iran’s supreme leader, intelligence chief, IRGC commander, and many others. “Iran may simply be waiting for the right opportunity to take revenge, perhaps waiting until the conflict is completely over and the risk of escalation is lower.”

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5 – Little strategic advantage

A fifth possibility is that Iranian leaders believe they do not need to resort to terrorism because their current response has already been successful. Drone attacks, missiles, shipping disruptions and proxy warfare have already allowed Tehran to impose costs and create an effective deterrent against a resumption of war. “In this context, terrorism may have proven redundant — offering little additional advantage while entailing disproportionate risks.”

Taken together, these explanations suggest that Iran’s containment is contingent, not permanent, says Byman. “Whether due to capacity limitations, strategic caution, or timing issues, the underlying logic that has long driven Iran’s use of terrorism may simply be dormant — for now.”