The Iran-Israel shadow war

What happened

For most of the past four decades, Iran and Israel fought each other through other people. Backing armed groups abroad has been a pillar of Iranian foreign policy since the Islamic Republic was founded in 1979, and the funding, training, weapons and equipment are coordinated by the Islamic Revolutionary Guard Corps, whose Qods Force is the component responsible for covert lethal operations outside Iran. ¹ The groups involved sometimes call the arrangement the "axis of resistance." They include Hezbollah in Lebanon, armed Shia militias in Iraq, the Houthis in Yemen, and Hamas, which Iran has supported going back nearly to the group's founding in the late 1980s. ¹

How much Tehran actually directs any of them is argued over. Some analysts describe the groups as appendages that follow orders from Iran. Others say they have their own origins and grievances, varying degrees of autonomy, and a symbiotic rather than subordinate relationship with Tehran. The U.S. Intelligence Community's 2025 Annual Threat Assessment split the difference and called the axis a loose consortium of like-minded terrorist and militant actors. ¹ On October 7 itself, the Intelligence Community's 2024 assessment concluded that Iran did not orchestrate the Hamas-led attack and had no foreknowledge of it. ¹

What Iran did do was activate the network afterward. Hezbollah began firing into Israel on October 8, 2023. Iraqi militias increased attacks on U.S. forces. The Houthis started attacking vessels in the Red Sea in November 2023 and launched drones and missiles at Israel. ¹

The direct phase began in 2024. On April 1, an Israeli strike in Damascus killed Iranian general Mohammad Reza Zahedi, who coordinated Iran's relationship with Hezbollah, at a building connected to an Iranian diplomatic site. ² On April 13 and 14, Iran fired roughly 300 drones and missiles at Israel, the first time it had ever attacked Israeli territory from its own soil. Israel, with the United States, the United Kingdom, France and Jordan, intercepted nearly all of it, and Israel answered with a limited strike on one military site near an Iranian nuclear installation. ² A second exchange followed in October 2024. Israel's strikes that month substantially degraded Iran's ballistic missile production capacity and its air defenses. ¹

By then the network was coming apart. Israel killed Hezbollah leader Hassan Nasrallah in a Beirut airstrike in September 2024, along with an IRGC general, and Hezbollah accepted a U.S.- and French-brokered ceasefire that November after losing much of its manpower and arsenal. ¹ In December 2024, Bashar al-Assad fled Syria, which removed Iran's land route to Lebanon. ¹

Israel struck Iran directly on June 13, 2025. The opening attacks degraded Iranian air defenses and missile bases, hit nuclear sites across the country, and killed Iran's military chief of staff, the commanders of the IRGC, the IRGC Air Force and the IRGC-Qods Force, an advisor to Khamenei on nuclear negotiations, and at least ten senior nuclear scientists. ³ Iran fired 150 missiles back the same day and called the attack a declaration of war in a letter to the U.N. Security Council. ³ On June 21 and 22 the United States struck Fordow, Natanz and Isfahan with seven B-2 bombers, more than 125 supporting aircraft, over two dozen Tomahawk missiles, and 14 GBU-57 bunker-busters, the first operational use of that weapon. ⁴ Iran hit Al Udeid Air Base in Qatar on June 23 with no casualties, and hostilities ended on June 24, twelve days after they began. ⁵

That ceasefire did not hold. After anti-government protests in Iran in December 2025 and January 2026 were put down in a crackdown that killed thousands, the United States and Israel began striking Iran again on February 28, 2026. ⁵ Israel killed Supreme Leader Ali Khamenei, in office since 1989, and dozens of other senior figures; his son Mojtaba Khamenei was appointed to replace him. ⁵⁶ By March 25, U.S. Central Command reported strikes on more than 10,000 targets in Iran, and shipping through the Strait of Hormuz had effectively stopped. ⁵

Why it still matters

U.S. assessments hold that Iran had a nuclear weapons program until late 2003 and does not have one now. ¹³ What changed is the material. After the United States stopped performing its commitments under the 2015 nuclear deal in 2018, Iran exceeded the deal's limits on enrichment and stockpiles. ¹ By March 2025, U.S. officials were saying Iran's enriched uranium stockpile was at its highest level ever and unprecedented for a state without nuclear weapons. ³ The IAEA assessed that Iran held roughly 400 kilograms of uranium enriched to 60 percent, and going from 60 to weapons-grade takes relatively little additional effort. ⁴¹ In October 2024 the CIA director said Iran could produce enough weapons-grade material for one weapon in about a week. ¹

The strikes have not settled it. Israeli military officials told the New York Times that Fordow was substantially damaged but not destroyed, and the 400 kilograms remained under Iranian control. ⁴ Israel itself has presumably maintained a nuclear arsenal for decades without officially acknowledging it, and has twice before destroyed a neighbor's nuclear facility, in Iraq in 1981 and Syria in 2007. ³

The cost has landed well outside Iran and Israel. As of late March 2026, more than 3,000 people had been reported killed in Iran and more than 1,000 in Lebanon, alongside 13 U.S. service members, 16 Israeli civilians and 3 Israeli soldiers. ⁵ On the first day, a U.S. Tomahawk hit a school in Minab and killed 168 people, most of them children; a preliminary U.S. military investigation found the United States responsible and blamed outdated targeting information. ⁵ Over 40 percent of Iran's return fire was aimed at the United Arab Emirates, not Israel. ⁵ Roughly 3.2 million Iranians have been displaced. ⁶

A Pakistan-mediated agreement in June 2026 paused large-scale fighting and reopened the Strait of Hormuz, and both sides have since accused each other of violating it. The core disputes it left open are enrichment, the Strait, and sanctions relief. As of August 2026, Iran has closed the Strait again and is demanding that the United States lift sanctions and pay reparations. ⁶

The words you'll hear

Axis of resistance. The name Iran-backed groups sometimes use for their network, described by the U.S. Intelligence Community's 2025 threat assessment as a loose consortium of like-minded terrorist and militant actors. ¹

IRGC-Qods Force. The branch of Iran's Revolutionary Guard responsible for covert lethal activities outside Iran, and the body that coordinates support to the groups above. Both the IRGC and the Qods Force are designated under U.S. terrorism sanctions authorities. ¹

Breakout. The time Iran would need to enrich enough weapons-grade uranium for a single weapon. The CIA director put it at about a week in October 2024. ¹

Fordow. Iran's deep underground enrichment facility, the target of 14 GBU-57 bunker-busting bombs on June 22, 2025, and reported afterward by Israeli officers as substantially damaged but not destroyed. ⁴

Snapback. The provision of U.N. Security Council Resolution 2231 that lets any participant in the 2015 nuclear deal move to reimpose the U.N. sanctions the deal had lifted. The British, French and German ambassadors said in December 2024 they were prepared to use it. ¹

Strait of Hormuz. The shipping channel between Iran and the Arabian Peninsula. Commercial traffic through it effectively halted during the 2026 fighting, disrupting global markets for oil, natural gas and other commodities. ⁵