[Q&A] How War Between Iran and Israel Could Escalate—and Drag In the United States

A Conversation with Daniel Benjamin Shapiro,  former American diplomat who served as United States Ambassador to Israel from 2011 to 2017.

On the evening of June 12, Israel launched a series of major strikes against Iran. The targets included Iranian nuclear facilities, missile sites, and multiple senior military and political officials. In a televised speech, Israeli Prime Minister Benjamin Netanyahu declared success. Iranian officials, meanwhile, swore revenge. Leaders across the region braced for unrest.

To better understand what Israel’s strikes might mean, Foreign Affairs senior editor Daniel Block spoke with Daniel B. Shapiro. Shapiro served as Deputy Assistant Secretary of Defense for the Middle East until January—charged with, among other things, considering scenarios in which tensions between Israel and Iran escalated into all-out war and preparing U.S. options for responding. Now a Distinguished Fellow at the Atlantic Council, Shapiro has also served as U.S. Ambassador to Israel and Senior Director for the Middle East and North Africa on the National Security Council. Their conversation has been edited for length and clarity.

Just how big a deal are these attacks? How much more serious are they than were the Israeli attacks on Iran in April and October of last year?

 The full extent of Israel’s strikes on Iran has not yet been revealed. But they are orders of magnitude beyond what Israel achieved in its April and October 2024 attacks. It is already clear that Israel was able to strike key nuclear sites, such as the Natanz enrichment facility, locations associated with possible weaponization research, ballistic missile launch sites, and numerous senior regime leaders and figures involved in Iran’s nuclear program. That is far

As the details emerge, the degree of Israel’s penetration of Iran’s system will further embarrass the regime. Iran will be highly motivated to respond, but its ability to do so meaningfully in the near term will be hampered by the leadership chaos the strikes have sown. What’s still unclear is the extent of the damage to nonofficial sites, or the civilian casualties. But Iran will probably try to match any losses they suffered in the civilian sphere, in addition to attacking Israeli military, intelligence, and leadership targets.

So far, the Trump administration has firmly distanced itself from these strikes. Why do you think that is?

 Trump had sought additional time from Netanyahu for nuclear talks, and Netanyahu did not give it to him. By distancing himself from Netanyahu’s decision, Trump is seeking to deter Iran from directing any response against the United States. Trump may also hope that he can keep nuclear negotiations alive. But his dream of a diplomatic resolution which ends Iranian nuclear enrichment appears dead. Iran is now far more likely to try to sprint to a nuclear breakout, leaving Trump with the dilemma of whether he will need to act militarily to prevent it.

What do you make of U.S. Secretary of State Marco Rubio’s statement promising to protect Americans, but notably omitting Israel?

 Rubio’s statement was intended to signal to Iran that the United States was not involved, and that Israel acted unilaterally. The omission of Israel is a further indication that Washington does not want to be seen as having endorsed the Israeli action. But it is inconceivable that U.S. officials did not have prior knowledge.

Rubio’s statement does not mean the United States won’t assist in Israel’s defense. It will.

Why did Israel decide to strike now, despite Trump’s apparent wishes?

 Netanyahu has long promised Israelis that he won’t let Iran develop a nuclear weapon. It has been central to his political career. And I think he sensed that Israel might never have a better opportunity to strike Iranian nuclear facilities. Israel decimated Iran’s Lebanese proxy, Hezbollah, in September 2024. It then destroyed Iran’s Russian-provided S-300 air defense batteries—Tehran’s most sophisticated—in October. Those two successes, combined with the fall of Iran’s key regional ally, the Assad regime in Syria, have left Iran with far less ability to defend its nuclear sites or retaliate.

How can we expect the Iranian response to unfold? And how will Israel’s defense play out?

 Iran may try to launch as many as several hundred ballistic missiles at Israel. This is in keeping with how it responded to past Israeli actions. After Israel killed a key Iranian leader in Damascus in April 2024, Iran lobbed over 300 munitions, including over 100 medium range ballistic missiles, at Israel. In October, after Israel decimated Hezbollah in Lebanon, Iran launched double the number of ballistic missiles. In April, Israel was able to avoid serious damage thanks to both its own air defenses and those of a U.S.-led coalition. But the October attack scored a few dozen hits that caused relatively minor damage. And earlier in June, Iran specifically pledged to strike Israel’s own nuclear facilities in response to this kind of attack.

By concentrating its defenses on certain sensitive sites and civilian populations, Israel, with U.S. support, will probably attempt to prevent its air defenses from being saturated and minimize damage, as it did against Iran’s two previous attacks. The United States has positioned two THAAD (Theater High-Altitude Area Defense) batteries in Israel to help. This system supplements Israel’s Arrow missile defense, as well as nearby U.S. naval vessels with missile defense capability.

The conflict is also unlikely to be over even if Iran quickly backs down.

Israel will also almost certainly face additional attacks from the Houthis in Yemen. Hezbollah, even in its weakened state, might be called upon to retaliate as well. But the Houthis are unlikely to be able to generate a major barrage. And Hezbollah’s reduced capabilities will limit its impact, as might pressure from the new Lebanese government.

Will Israel respond to Iran’s retaliation with more strikes?

 Netanyahu said Israeli strikes would continue until Israel is satisfied that the threat of a nuclear Iran is gone. So we may be looking at something more like a campaign, rather than a one-off attack. Whether Israel will then feel the need to respond to Iran’s attempts at retaliation is going to depend very much on the level of damage and casualties it sustains. So a successful defense against Iranian missiles could have a deescalatory effect, whereas significant casualties will almost certainly lead Israel to seek to strike Iran again.

Last October, Israel sought to coordinate its response to an Iranian attack with Washington, which gave U.S. President Joe Biden opportunities to shape and limit the Israeli response. But Israel showed little interest in such coordination this time, and Trump may also find it is not worthwhile. This could mean Iran finds it more difficult to move down the escalation ladder.

The conflict is also unlikely to be over even if the Iranian military quickly backs down. Israel should expect an ongoing series of asymmetric attacks, such as cyber operations and terrorist attacks against its embassies, travelers, and businesses.

What is the likelihood that Iran attacks U.S. forces?

Much depends on messaging from the United States. Trump has made clear that Washington was not involved in the Israeli strikes and warned Iran not to target U.S. forces. If Iranian leaders understand that by engaging the United States or others in the region, it faces the risk of a direct U.S. attack that would compound the damage Israel has already caused, it is more likely to limit its response to attacks against Israel. It may well downgrade its cooperation with the International Atomic Energy Agency and try to rebuild and further bury and harden its remaining nuclear infrastructure. But Iran may choose not to attack actors other than Israel, in order to keep them out of the war.

Let’s say that Iran does attack the United States, prompting U.S. retaliation, or that Washington decides to get directly involved to prevent an Iranian nuclear breakout. How might an American attack on Iran play out?

 Some of the assets that would facilitate an American strike are already available. The USS Carl Vinson carrier strike group continues to be deployed to the region. Before a strike, a second carrier strike group might sail toward the area. Additional aircraft, such as fighter squadrons, tankers, and search and rescue helicopters, would likely also be deployed to bases in the region. The United States also has unique capabilities it could employ if it intended to target Iran’s deeply buried enrichment facility at Fordow.

How would Iran handle direct United States involvement?

 Iran would not absorb American strikes without retaliating. Iran possesses an arsenal of thousands of close-range ballistic missiles and drones that it could launch at American bases in Bahrain, Kuwait, Qatar, Saudi Arabia, and the United Arab Emirates. It used such missiles to attack U.S. forces following Washington’s assassination of Qasem Soleimani, the commander of Iran’s Quds Force, in 2020.

Iran will now likely make a desperate run to nuclear breakout.

Shiite militia groups in Iraq and Syria, armed with Iranian drones, could fire at U.S. bases as they did for several months following October 7, 2023. They might also target the U.S. embassy in Baghdad. Troops and personnel at these locations may need to spend significant periods in shelters. Air defense assets at specific locations could be outnumbered by incoming munitions. There would be a risk of American casualties. The United States would need to press the Iraqi government to prevent Shiite militias from joining the fight, which it has done successfully since mid-2024. American forces would have to be prepared to strike militias that attack them, as they did several times last year. And the United States and regional governments would need to push the Houthis not to resume attacks in the Red Sea. They would need to be prepared to resume strikes if the Houthis resume them. Washington would also need to prepare for asymmetric attacks both in the region and in the United States itself.

Could Iran or its partners decide to attack Arab states, as they have in the past?

 The Gulf states will likely condemn the Israeli attack in order to dissuade Iran from hitting their territory and assets. But if the United States gets involved, Iran might well fire close-range ballistic missiles at civilian locations or energy infrastructure in the Gulf states, in order to exact a price for what they would see as complicity with a U.S. attack.

Iran would also consider an effort to shut down the Strait of Hormuz to oil and gas tankers using a naval blockade, sea mines, limpet mines deployed by fast boats, or some combination thereof. Saudi Arabia and the UAE possess significant air defense assets, but all of these countries would still be vulnerable to strikes.

What does this war mean for the future of Iran’s nuclear program?

 Most estimates suggested Israel, on its own, could set back the Iranian nuclear program by several months. Public reports have estimated that U.S. strikes, meanwhile, could set the Iranian nuclear program back by up to a year. But those timelines assume Iran immediately starts rebuilding, and they do not take into account additional delays that could occur based on economic or political factors. Those estimates also do not account for the impact of deterrence or potential restrikes.

But it is likely that Iran will now make a desperate run to nuclear breakout. Trump, in turn, will be faced with a decision about whether to intervene militarily to prevent an Iranian nuclear weapon. That decision will split his advisers and political base, given his long-stated determination to keep the United States out of Middle East wars.

[ForeignAffairs]