Iran is the principal financial backer of Hamas. It provides weapons and training for terrorists in Lebanon and Iran. Representatives of Hamas and Palestinian Islamic Jihad (PIJ) met with Iranian military officials in 2021. Some 500 fighters from the two groups were in Iran for military exercises in September 2023.

In the early days of the fighting, it was not clear what role Iran may have played in the planning and implementation of the attack on Israel. U.S. officials have insisted Iran was surprised by the assault.

No one questioned the Iranian objective of forcing Israel to confront a possible multifront war with its proxies in Lebanon and Gaza or its incentive to derail U.S. efforts to negotiate a deal with Saudi Arabia to normalize relations with Israel.

While denying any involvement, Iran’s supreme leader, Ayatollah Ali Khamenei, praised Hamas. “We kiss the foreheads and arms of the resourceful and intelligent designers,” he said.

The Wall Street Journal reported that Iranian President Ebrahim Raisi spoke to leaders of Hamas and Palestinian Islamic Jihad (PIJ) and “congratulated the Palestinian people on the victories of the resistance and emphasized Iran’s support for the people and the resistance.” Raisi added that “Iran supports the resistance and the Palestinian people, and that you bring happiness to the Islamic nation with this initiative.”

The Journal said that the Islamic Revolutionary Guard Corps helped Hamas devise the attack and that meetings had been held for weeks in Lebanon before final approval was given a few days before it was launched.

Israel blamed Iran, but the United States insisted it had no evidence of Iran’s direct involvement. Critics suggested the administration was reluctant to assign blame for fear it would prompt calls for action against Iran or undermine efforts to negotiate Iran’s return to compliance with the nuclear deal. Some still called on the president to cancel the transfer of $6 billion in Iranian assets that had been arranged in exchange for the release of American hostages. The administration subsequently declared that none of this money, which is in a Qatari bank, had been released.

IDF Spokesman Rear Adm. Daniel Hagari said at a press conference on October 25 that “Iran directly aided Hamas before the war, with training, supplying weapons, money and technological know-how.” He added, “Even now, Iranian aid to Hamas continues in the form of intelligence and online incitement against the State of Israel.”

Hamas official Khaled Meshaal acknowledged that “Hezbollah and Iran supported us with weapons, expertise, and technology.”

Khamenei accused the United States of helping Israel. “The United States is in some way directing the crime that is being committed in Gaza,” he said, suggesting the hands of Americans “were tainted with the blood of the oppressed, children, patients, women, and others.”

A Hamas delegation met Iranian officials in Moscow.

On November 25, a Malta-flagged ship owned by an Israeli was attacked by a suspected Iranian drone in the Indian Ocean. The drone exploded, causing damage to the ship but not injuring any of its crew.

Speaking at the funeral for victims of an ISIS bombing, Iranian President Raisi said, “We know that ‘Al-Aqsa Flood’ operation will bring about the end of the Zionist regime.”

Israel continued to target Iranian officials and, on March 2, 2024, killed Rada Zarai, a commander of the Islamic Revolutionary Guards Corps’ elite Quds Force, and two others in a strike in Syria.

Iran-backed Iraqi militias also launched attacks on Israel. In one instance, an Israeli navy base in Eilat was hit and damaged. In most instances, drone attacks from the Islamic Resistance in Iraq were thwarted.

On April 1, 2024, Israel dramatically escalated the fight with Iran when it bombed a building that Iranians claimed was a consulate. The strike killed Gen. Mohamad Reza Zahedi, who oversaw Iran’s covert military operations in Syria and Lebanon, two other generals, and four officers in the Quds Force. It would be unusual for IRGC officers to work out of a consulate rather than the embassy. Still, Iran may have believed the building would have been regarded as equally protected as a diplomatic office. Iran and Hezbollah vowed revenge and said Israeli embassies were no longer safe. Israel said it was prepared for any threat.

On April 13, 170 drones, 30 cruise missiles, and 120 ballistic missiles were launched at Israel from Iran, Iraq, Syria, and Yemen. Israel, the United States, and other allies intercepted 99% of the threats. Only one Israeli, a young Bedouin girl, was injured, and only minor damage was caused to an air base.

“You got a win. Take the win,” Biden told Netanyahu. He advised Israel to “slow things down and think through” how to respond.

Sardar Bagheri, the Chief of Staff of Iran’s Armed Forces, said that from Iran’s perspective, the military operation against Israel “has concluded.” He warned, however, “If the Zionist regime responds, our next operation will be much bigger” (CNN, April 14, 2024).

Israel pledged that it would “exact a price” from Iran but immediately came under pressure from Biden not to escalate.

Months later, as calls intensified for Biden to withdraw from the presidential race because of fears about his ability to defeat Trump given his apparent mental decline, administration officials leaked to the New York Times the contents of the president’s phone conversation with Netanyahu after Iran launched its missile and drone attack on Israel on April 14. The intent was to demonstrate Biden was in command of his faculties.

“Let me be crystal clear, if you launch a big attack on Iran, you are on your own,” Biden reportedly said. To Netanyahu’s argument that a strong response was needed to deter Iran, Biden replied, “You do this and I’m out.”

This was yet another example of the U.S. trying to prevent Israel from eliminating the Iranian nuclear threat out of fear it would spark a broader war that the U.S. was determined to stay out of. Biden specifically told Israel not to attack Iranian nuclear or energy sites.

The U.S. was prepared to help so long as Israel played by Biden’s rules. Gallant said he asked Austin for five things: Permission to fly over Iraq, intel from satellites Israel didn’t have, help rescuing pilots if any planes were shot down, additional missiles for the Arrow, and refueling of Israeli jets by American tankers. Within hours, the administration approved the requests for everything but the refueling tankers to avoid direct involvement in any operation

On April 18, Israel launched a retaliatory strike targeting Isfahan and Tabriz, destroying its air defenses but not hitting the nuclear facilities. Israel reportedly used drones and fired missiles from Iraqi airspace. The relative pinprick satisfied Biden but was much less robust than what Israel planned and its public expected. For their part, the Iranians played down the attack to avoid further escalation and to conceal from its public how vulnerable the country was to the Israeli attack and how much weaker it was afterward.

On July 9, 2024, Director of National Intelligence Avril Haines released a statement disclosing Iranian influence on protests against the Gaza war in the United States.

In recent weeks, Iranian government actors have sought to opportunistically take advantage of ongoing protests regarding the war in Gaza, using a playbook we’ve seen other actors use over the years. We have observed actors tied to Iran’s government posing as activists online, seeking to encourage protests and even providing financial support to protesters.

Iranian Supreme Leader Ali Khamenei ordered a direct attack on Israel following the assassination of Hamas terror chief Ismail Haniyeh in Tehran on July 31. Iran and Hamas accused Israel of the assassination, which occurred during Haniyeh’s visit to Tehran for President Masoud Pezeshkian’s inauguration. Iran’s potential retaliation may involve launching drones and missiles at military targets near Tel Aviv and Haifa or coordinating with regional proxies such as Hezbollah, the Houthis, and militias in Iraq and Syria.

In response to the heightened threat, Netanyahu and government ministers increased security measures at public events. Israeli embassies worldwide raised their alert levels.

The U.S. moved additional military assets to the Mediterranean as a deterrent. “If Israel is attacked, yes, we will help Israel defend itself,” said Austin. “We’ve been clear about that from the very beginning. We don’t want to see that happen; what we want to see is things resolved in a diplomatic fashion.” Austin also said he had ordered the USS Abraham Lincoln to the region and more cruisers and destroyers capable of ballistic missile defense. Additional squadrons of F/A 18 Hornets and F-22 fighter jets were also sent to reinforce defensive air support capabilities. The U.S. also said it deployed a submarine.

Gallant and Austin were in close contact to discuss “interoperability with the wide range of U.S. military capabilities deployed to the region.”

Russia reportedly sent additional air defense systems to Iran, while President Putin cautioned Iran against attacking any Israeli targets that could cause civilian casualties.

On September 27, 2024, Israel bombed Hezbollah’s headquarters in Beirut to assassinate Hezbollah chief Hassan Nasrallah. Also killed was the commander of the Quds Force of the Revolutionary Guards in Syria and Lebanon, Iranian General Abbas Nilforushan. Iran vowed revenge for those deaths and the assassination of Ismail Haniyeh.

The retribution came on October 1, when Iran launched 181 ballistic missiles at Israel. Israeli and U.S. air defenses shot down most. Iran claimed it aimed at three military bases — Nevatim, Hatzerim, and Tel Nof — and the headquarters of the Mossad, but missiles were shot down over cities and areas nowhere near military facilities. The New York Times reported missiles at the Navatim air base in the Negev, but the IDF said it had no impact on the IAF’s operational capability. Another missile hit a school in Gedera in central Israel. No injuries were reported. A missile also fell between homes in a Palestinian village on the West Bank. The only known casualty was a Palestinian hit by rocket fragments in Jericho in the West Bank. Still, this represented an escalation, with Israel predictably declaring it would respond.

A map of Israel highlighting the regions targeted
by Iran’s missile barrage on October 1, 2024.

“Iran made a big mistake tonight — and it will pay for it,” Netanyahu declared. “The regime in Iran does not understand our determination to defend ourselves and to retaliate against our enemies.”

“Based on what we know now, the attack appears to have been defeated and ineffective,” President Biden said, acknowledging that the U.S. military “actively supported” Israel’s defense. He added, “Make no mistake, the United States is fully, fully, fully supportive of Israel.”

Jordan reported it had intercepted missiles, and the falling fragments injured two people.

As Israel contemplated its response to the Iranian attack, President Biden said he would not support any Israeli strike on Iran’s nuclear sites. “We'll be discussing with the Israelis what they're going to do, but all seven of us (G7 nations) agree that they have a right to respond but they should respond proportionally,” he said. His national security adviser, Jake Sullivan, said earlier “that there will be consequences - severe consequences - for this attack.”

In Britain, Prime Minister Keir Starmer used the anniversary of the October 7, 2023 attack to urge the international community to turn its focus on the “malign” regime in Iran. He told Parliament that the ayatollahs must be held to account and forced to take responsibility for the humanitarian crisis unfolding in the region.

“We support Israel’s right to defend herself against Iran’s aggression, in line with international law, because, let’s be very clear, this was not a defensive action by Iran, it was an act of aggression and a major escalation in response to the death of a terrorist leader,” he said.

“It exposes, once again, Iran’s malign role in the region: they helped equip Hamas for the seventh of October attacks, they armed Hezbollah, who launched a year-long barrage of rockets on northern Israel, forcing 60,000 Israelis to flee their homes, and they support the Houthis, who mount direct attacks on Israel and continue to attack international shipping.”

To defend Israel against a possible attack by Iran in retaliation for an Israeli strike on Iranian targets, the United States deployed its advanced THAAD (Terminal High-Altitude Area Defense) anti-ballistic missile system in Israel with a force of 100 to operate it.

A drone fired from Lebanon hit the bedroom window of Prime Minister Benjamin Netanyahu’s home in Caesarea on October 19, 2024, in an apparent assassination attempt. The Netanyahus were not home then, and no one was injured. Hezbollah took credit, but Israel blamed Iran. Netanyahu vowed that anyone who harmed Israelis would pay “a heavy price.”

Table of Contents for Israel-Hamas War
Bibliography

The Israel-Hamas War: The Iranian Role