A SHADOW war between Israel and Iran has shaped the Middle East for decades. Of the many conflicts that have roiled the region, theirs has long been among the most explosive. The two have attacked each other – mostly quietly and in Iran’s case often by proxy – while avoiding an escalation into direct war.

But as the fighting between Israel and the Iran-backed Palestinian group Hamas continues, the shadow war has entered a dangerous new phase. Other militant groups supported by Iran have joined the fray. On Jan 15, Iran used missiles to attack what it said was an Israeli spy base in Iraq. Five days later, Iran blamed Israel for a rocket strike on a building in the Syrian capital Damascus housing Iranian military advisers.

Why are Iran and Israel enemies?

They were allies starting in the 1950s during the reign of Iran’s last monarch, Shah Mohammad Reza Pahlavi, but the friendship abruptly ended with the Islamic revolution in Iran in 1979.

The country’s new leaders adopted a strong anti-Israel stance, decrying the Jewish state as an imperialist power in the Middle East. Iran has supported groups that regularly fight Israel, notably Hamas, which the US and European Union consider a terrorist group, and the Hizbollah militia in Lebanon.

Israel regards Iran’s potential to build nuclear weapons as a threat to its existence and is thought to be behind a campaign of sabotage against the country’s atomic programme. Iran’s leaders say they have no ambition to build nuclear weapons. The Israelis point to a cache of documents their intelligence agents spirited out of Iran in 2018 that suggests otherwise.

Israeli officials have repeatedly implied that if Iran were to reach the brink of weapons capability, they would attack its nuclear programme using air power, as they did Iraq’s in 1981 and Syria’s in 2007.

GET BT IN YOUR INBOX DAILY

Start and end each day with the latest news stories and analyses delivered straight to your inbox.

Sign UpVIEW ALL

Where is the shadow war fought?

Lebanon is the oldest front in the battle, which is fought indirectly. In reaction to Israel’s invasion of the country’s south in 1982, a militia that would become Hizbollah was formed by Lebanese Muslims belonging to the Shiite branch of Islam dominant in Iran. Their group to some extent became a proxy for Iran’s premier security force, the Islamic Revolutionary Guard Corps.

Israel and Hizbollah have fought repeatedly, including in a war in 2006. Since Oct 7, 2023, Hizbollah has expressed solidarity with Hamas by firing missiles, mortars and rockets into Israel almost daily, prompting Israel to respond with its own fire.

The shadow war is also being waged in Syria. Through the course of Syria’s civil war, Iran has built up a military presence in the country to support its ally, President Bashar al-Assad, and to facilitate the transfer by land of weaponry meant for Hizbollah from Iran to Lebanon via Iraq and Syria. In an effort to stop the arms flow and counter this second hostile presence on its northern border, Israel has carried out hundreds of strikes inside Syria against arms shipments and other targets it says are linked to Iran and its allies, in some cases killing Iranians, according to media accounts.

After Oct 7, 2023, Israel stepped up strikes against Iran-backed militias in Syria after they moved close to the Israeli border. On Dec 25, Iran said an Israeli air strike in Damascus killed a senior Revolutionary Guard commander. Among those killed in the subsequent attack in Damascus, on Jan 20, were the intelligence chief of the Quds Force, which is primarily responsible for the Guards’ foreign operations, and his deputy, according to Iran’s state-run Student News Network.

Iraq is yet another front. Iran said its Jan 15 attack on what it called an Israeli “espionage headquarters” in Iraq’s autonomous Kurdistan region was retaliation for the Dec 25 strike in Damascus. Iran has launched multiple attacks on Kurdistan since late 2022. It accuses separatist Kurdish groups in the region of collaborating with foreign security services against it. Israel has in the past used facilities in northern Iraq to gather intelligence on Iran, according to multiple reports.

The shadow war is also fought at sea. Tit-for-tat attacks on commercial vessels began in 2019. Although neither Israel nor Iran has accepted responsibility for the hits on ships connected to the other, they are widely thought to be behind them.

Loss of life has been rare, but in July 2021, a British and a Romanian crew member were killed when an Israeli-operated ship was struck in the Gulf of Oman by a drone that US officials linked to Iran. Previous targets have included Iranian tankers carrying oil destined for Syria; an Iranian ship off the coast of Yemen that served as a floating base for the Revolutionary Guards; and cargo ships belonging to or linked to Israelis.

In an escalation of the attacks at sea, since Oct 7, 2023, Iranian-backed Houthi rebels, who have controlled north-western Yemen since civil war broke out in 2014, have attempted to strike Israel with missiles and drones and have repeatedly attacked ships in the Red Sea. They say they are targeting Israel-linked vessels, but ships with no such direction connection have been hit.

What about attacks inside the two countries?

Though Iran has mostly absorbed Israeli strikes on its interests in Syria, in 2018 its forces there fired a barrage of missiles toward Israeli positions in the Golan Heights, a plateau Israel captured from Syria in the 1967 war and later annexed. Israel replied with a much greater show of force.

For its part, Israel is widely thought to be behind the assassination in Tehran of five Iranian nuclear scientists since 2010 and several attacks on nuclear sites inside Iran.

In April 2021, Iran blamed Israel and vowed revenge for an explosion at its largest uranium enrichment facility in Natanz, which it said caused significant damage to its centrifuges. It was the second time in less than a year that the site had been hit by a suspicious blast. Israel neither confirmed nor denied it was responsible for either attack.

In October 2021, an Iranian general said Israel was likely behind a cyberattack that paralysed gas stations across Iran. And in January 2023, after an Iranian ammunition depot near the central city of Isfahan was attacked in a drone strike, two US newspapers reported that Israel was responsible. BLOOMBERG