Reports that Iran is preparing reprisal attacks following the deadly bombing of a facility that Israel claims is linked to threats against its interests have provoked fears of conflict widening in the Middle East.

U.S. President Joe Biden has vowed “ironclad” support for Israel, which is widely considered to be responsible for the April 1, 2024, attack, amid fiery rhetoric from Tehran warning of revenge.

But what could an Iranian response look like? And how is Tehran thinking about the associated pros and cons of any such activity? The Conversation U.S. turned to Javed Ali, a national security expert at the University of Michigan and former senior U.S. counterterrorism official, for answers.

How has the Damascus attack changed the calculus in Tehran?

The attack in Damascus – which the Israeli government has yet to acknowledge publicly – was a dramatic turn in the long-running shadow war between Israel and Iran.

For decades now, both Iran and Israel have engaged in operations against each other in both the physical and virtual worlds.

These attacks have involved cyberoperations, support to proxy forces, airstrikes and targeted killings that have taken a toll on both sides.

The Damascus attack was particularly dramatic, however, because it killed two generals and five other officers in the Islamic Revolutionary Guards Corps’ Quds Force. The Quds Force is Iran’s unconventional warfare wing that has supported Tehran’s proxies and regional partners with money, weapons and equipment for decades. Moreover, it took place on a diplomatic enclave, which Israel had not previously conducted operations against, even in Damascus.

In the history of the Quds Force, it had never lost that many officers in one operation by its adversaries. Even the significant U.S. attack against former Quds Force chief Qassem Soleimani in January 2020 did not kill other senior members of the organization.

In addition, Mohammad Zahedi, one of the generals killed in the April 1 attack, was directly responsible for managing relationships with Hezbollah in Lebanon, the Syrian government and Shia militias in that country, and Hamas and Palestinian Islamic Jihad in Gaza and the West Bank.

What have the US, Israel and Iran said about reprisal attacks?

Immediately after the attack, Iranian officials, including Supreme Leader Ayatollah Khamenei, publicly blamed Israel and vowed revenge. Iran’s Foreign Minister Hossein Amir said, “We consider this aggression to have violated all diplomatic norms and international treaties. (Israeli Prime Minister) Benjamin Netanyahu has completely lost his mental balance due to the successive failures in Gaza and his failure to achieve his Zionist goals.”

From the Israeli perspective, even though there was no official acknowledgment of the Damascus operation, Israel Defense Forces spokesperson Rear Adm. Daniel Hagari said that the building hit was not a diplomatic facility but a location where Quds Force officials would meet their partners in the region to advance operations against Israel.

Many news outlets have reported that unidentified U.S. officials believe a major Iranian ballistic missile or drone strike on Israel is imminent.

If true, this would mirror how Iran responded to the death of Qassem Soleimani in January 2020 by firing ballistic missiles at U.S. forces stationed at al-Asad Air Base in western Iraq about two weeks later.

The United States has also indicated that it may assist Israel in responding to any Iranian direct attack, although the details of that are unclear.

What’s Iran’s philosophy on attacks against its interests?

Against the backdrop of the decades-long shadow war between Iran and Israel that has so far not erupted into larger-scale hostilities, Iran’s philosophy to date has been one of proportional and measured responses that try not to escalate the conflict.

While Khamenei said on April 10 that “the evil regime made a mistake and it should be punished and will be punished,” Iran will often wait days to weeks or even years before seeking retribution.

Tehran’s decision-making seems driven by a combination of factors. First, national security has been concentrated in the hands of the the supreme leader ever since the Iranian Revolution in 1979, meaning the ayatollah has ultimate say in Iran’s strategy and outlook.

Second, operational considerations regarding access to possible targets and Iran’s ability to inflict harm on them – regardless whether they are physical or virtual – are just as important.

And third, analysis of the implications of a successful reprisal attack – and how they could impact other important Iranian considerations and interests – very likely are at play. For example, is the supreme leader thinking about the possible risks of any Iranian response versus gains made on Iran’s nuclear program, its ability to circumvent U.S.-led sanctions against its economy, or domestic backlash should Israel conduct operations directly inside Iran?

What possible attack options could Iran be looking at?

With this framework in mind, a possible Iranian ballistic missile attack against Israeli diplomatic facilities in the region might be one option on the table. Indeed, Iran has already said that Israel’s embassies are “no longer safe” following the Damascus strike.

From the Iranian perspective, this would probably be perceived as proportional and not a widening of the ongoing conflict with Israel.

However, what that kind of attack would look like is difficult to assess, since it would have to be carried out in dense urban environments anywhere in the region. In such circumstances, the impact of a ballistic missile could cause a wider pattern of damage and civilian harm, potentially in a Muslim-majority country – something that could provoke a backlash in Iran or create diplomatic problems between Iran and other countries in the region.

Conversely, ballistic missile attacks against Israeli military targets directly in Israel – similar to what Iran carried out in the January 2020 al-Asad Air Base attack in Iraq – might be operationally feasible but be perceived by Israel as escalatory.

Tehran will be wary of any retaliatory strike that would invite a significant military response beyond Israel’s already aggressive posture against the IRGC and Quds Force.

Beyond ballistic missiles, Iran could turn to its partners and proxies in the region to attack Israeli interests with conventional weapons or unconventionally with terrorist attacks.

While there is a long pattern of such Iranian-backed terrorism against Israel both in the region and transnationally, including the Oct. 7 assault by Hamas, the supreme leader and other Iranian security officials may not choose that route since it could be seen as not coming directly from Iran and fitting the proportional and measured framework.

If Iran does respond, is that going to lead to a wider regional conflict?

That’s the $64,000 question. A wider conflict that draws in the U.S., Iran’s great regional rival Saudi Arabia and others is what security analysts, government officials and pretty much everyone else in the region have feared is the next step of the conflict.

The answer would lie in future unknowns, notably how Israel responds – and Prime Minister Benjamin Netanyahu has vowed to retaliate to any attack within its borders – then how Iran and others react to that.

With so many variables in play, it is difficult to know if an Iranian response to the attack in Damascus will restore deterrence in Tehran’s eyes or trigger a broader range of attacks by multiple parties that further destabilize an already volatile region.

Javed Ali does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.