Iran and Israel have been engaged in a proxy conflict since 1985. In the Israeli–Lebanese conflict, Iran has supported Lebanese Shia militias, most notably Hezbollah. In the Israeli–Palestinian conflict, Iran has backed Palestinian groups such as Hamas. Israel has supported Iranian rebels, conducted airstrikes against Iranian allies in Syria, assassinated Iranian nuclear scientists, and directly attacked Iranian forces in Syria. In 2024 the proxy war escalated to a series of direct confrontations between the two countries, and in June 2025, they fought a 12-day war, involving the United States. In 2026, Israel and the United States again engaged in another conflict against Iran in the 2026 Iran war, which caused series of spillovers in Iranian strikes on Arab countries and the 2026 Strait of Hormuz crisis.
Motivated by the periphery doctrine, Imperial Iran and Israel had close relations, seeing Arab powers as a common threat. After the 1979 Islamic revolution, Iran cut off relations, but covert ties continued during the subsequent Iran–Iraq War. Iran trained and armed Hezbollah to resist the Israel's 1982 invasion of Lebanon, and continued to back Shia militias throughout the Israeli occupation of Southern Lebanon. Even before 1979, Iranian Islamists had materially supported the Palestinians; after 1979 Iran attempted to form close relations with the Palestine Liberation Organization, and later with Palestinian Islamic Jihad and Hamas. Israel fought a war with Hezbollah in 2006. Israel has fought several wars with Palestinians in and around the Gaza Strip: in 2008–2009, 2012, 2014, 2021 and since 2023. The 1982 Lebanon War and Gaza war have been the deadliest wars of the Arab–Israeli conflict.
Various reasons have been given for the Iran–Israel conflict. Iran and Israel had previously enjoyed warm ties due to common threats, but by the 1990s the USSR had dissolved and Iraq had been weakened. Iranian Islamists have long championed the Palestinian people, whom they perceive as oppressed. Scholars believe that by supporting the Palestinians, Iran seeks greater acceptance among Sunnis and Arabs, both of whom dominate the Middle East. At times, Iran has supported the one-state and the two-state solution as a response to the plight of Palestinians, while the country has also used more inflammatory language to predict Israel's demise. Israel sees Iran as an existential threat. Israel has accused Iran of harboring genocidal intentions, while Iran has accused Israel of conducting a genocide in Gaza. Consequently, Israel has sought sanctions and military action against Iran to stop it from acquiring nuclear weapons. News outlets expressed how Iranian proxy militias stayed largely silent and left Iran "isolated in war" during the 2025 war with Israel.
Background
Iranian Islamists have a long history of sympathizing with the Palestinians. In 1949, Iranian ayatollah Mahmoud Taleghani visited the West Bank and was moved by the plight of Palestinian refugees. Taleghani began advocating for Palestinians in the 1950s and 1960s. After the Six-Day War in 1967, he raised funds (e.g. zakat) inside Iran to be sent to Palestinians. The Iranian government at the time was alarmed at these activities and SAVAK documents indicate that the government believed that the Iranian public was sympathetic to the Palestinian people. Likewise Ruhollah Khomeini championed the Palestinian people before he became Iran's Supreme Leader in 1979. He also criticized the Pahlavi dynasty's ties with Israel, viewing Israel as a supporter of the Pahlavi regime. Following the 1979 Iranian revolution, Khomeini's new government adopted a policy of hostility towards Israel. The new Iranian government saw Israel as a colonial outpost. Iran withdrew recognition of Israel as a state, and severed all diplomatic, commercial and other ties with Israel, referring to its government as the "Zionist regime" and Israel as "occupied Palestine".
Despite the tension between the two countries, Israel provided support to Iran during the Iran–Iraq War from 1980 to 1988. During the war, Israel was one of the main suppliers of military equipment to Iran and also provided military instructors. Israel gave direct support to Iran's war effort when it bombed and destroyed Iraq's Osirak nuclear reactor in Operation Babylon. The nuclear reactor was considered a central component of Iraq's nuclear weapons program.
The 1982 Israeli invasion of Lebanon resulted in the departures of the Palestine Liberation Organization (PLO) from Lebanon. The ensuing Israeli occupation of Southern Lebanon temporarily benefited Israeli allies in Lebanon and the civilian Israeli population with fewer violent attacks on Northern Israel by Hezbollah than previously by PLO in the 1970s. However, the Sabra and Shatila massacre perpetrated by Israeli proxies (the Maronite Lebanese Forces and right-wing Phalangists) against Lebanese Shias had as a long-term consequence the emergence of a homegrown Lebanese, rather than Palestinian, resistance movement within South Lebanon, which by the second half of the 1990s was posing more strategic trouble to Israel than the PLO could pose in the 1970s.
Iran has periodically called for the destruction of Israel. Iran has established a network of allies and proxy forces across the Middle East, which it describes as part of an "axis of resistance" aimed at opposing US and Israeli interests in the area. Israel views Iran as an existential threat on account of Tehran's rhetoric, its support for proxy forces in the region, and its arming and financing of Palestinian groups such as Hamas. In some cases, proxy groups evolved into political parties, a transition that was both encouraged and nurtured by Iran. These dual-role proxies earned political legitimacy while masking terrorist activities. U.S. intelligence officials said they believe Iran does not seek a broader conflict, arguing that the primary goal of Iranian proxies is to target Israel and the United States in a way that avoids triggering a large-scale war. The United States is considered to be Israel's largest "military backer". Germany, Britain, and Italy have also supplied weapons to Israel.
As detailed by the Stimson Center, Iran has historically employed at least four main fronts: Hamas in Gaza, Hezbollah in Lebanon, Shiʿite militias in Iraq, and the Houthis in Yemen. According to the report the goal is to compel Israel to defend on multiple fronts simultaneously, reducing its ability to focus on Iranian nuclear or military capabilities and pressure Israel indirectly.
History
Relationship with PLO
Starting in the 1960s, many Iranians (both leftist and religious) had volunteered to fight against Israel with various Palestinian organizations, including the Palestinian Liberation Organization (PLO). Some of these volunteers, who had received training in Lebanon and Jordan, then returned to Iran to fight against the Shah.
Yasser Arafat visited Iran on 17 February 1979, becoming the first foreign leader to visit the country after the Islamic Revolution. During Arafat's visit, Iran severed ties with Israel and expelled Israeli diplomats. The PLO found Iran's revolution inspiring, given that Khomenei, who had been exiled from his homeland, defeated a militarily powerful enemy supported by the US, something that the PLO thought it could replicate against Israel. On the other hand, Palestinians felt Arab nationalism was at a dead end. Arabs were defeated in the 1967 war, Jordan expelled the PLO in 1970 and Egypt recognized Israel in 1978.
During the Iran hostage crisis, the PLO attempted to mediate with the Iranian students, but failed. In addition, secret documents were allegedly discovered at the US embassy detailing Israeli support for the Shah's regime.
At the start of the Iran–Iraq War, Yasser Arafat tried to mediate between Saddam Hussein and Khomenei. Arafat feared the war would distract from the Palestinian cause. Arafat travelled personally on 20 September 1980, to Baghdad and Tehran, but his efforts were unsuccessful. Arafat eventually sided with Iraq during the war. Despite this, Iranian leaders kept a pro-Palestinian stance.
Iran under Khomeini (1979–1989)
Following the Iranian Revolution and the fall of the Pahlavi dynasty in 1979, Iran adopted a strong anti-Israel stance. Iran cut off all official relations with Israel. Iran also ceased to accept Israeli passports, and the holders of Iranian passports were banned from travelling to "the occupied Palestine". The Israeli Embassy in Tehran was closed and handed over to the PLO. Ayatollah Khomeini declared Israel an "enemy of Islam" and the "Little Satan". The United States was called the "Great Satan" while the Soviet Union was called the "Lesser Satan". Iran provided support for Islamist-Shia Lebanese parties, helping to consolidate them into a single political and military organization, Hezbollah, and providing them the ideological indoctrination, military training and equipment to attack Israeli and American targets.
Israeli occupation of Lebanon
In 1982, Israel invaded Lebanon. The leaders of the Lebanese Shia community appealed to Iran for help. Khomeini sent his defense minister and military leaders to Syria to assist, however he eventually concluded that Iran could not fight a two-front war given its ongoing war with Iraq.
Despite Israeli success in eradicating PLO bases and partial withdrawal in 1985, the Israeli invasion had actually increased the severity of conflict with local Lebanese militias and resulted in the consolidation of several local Shia Muslim movements in Lebanon, including Hezbollah and Amal, from a previously unorganized guerrilla movement in the south. Over the years, military casualties of both sides grew higher, as both parties used more modern weaponry, and Hezbollah progressed in its tactics.
Iran supplied the militant organization Hezbollah with substantial amounts of training, weapons, explosives, financial, political, diplomatic, and organizational aid while persuading Hezbollah to take action against Israel. Hezbollah's 1985 manifesto listed among its four main goals "Israel's final departure from Lebanon as a prelude to its final obliteration." According to reports released in February 2010, Hezbollah received $400 million from Iran. By the early 1990s, Hezbollah, with support from Syria and Iran, emerged as the leading group and military power, monopolizing the directorship of the guerrilla activity in South Lebanon.
2000s
Shabaa Farms conflict
Since Israel withdrew from Southern Lebanon and Hezbollah took over the assets of the South Lebanon Army in May 2000, the conflict continued at low-level, centering around the Shabaa Farms region.
With the election of Iranian hardliner Mahmoud Ahmadinejad in 2005, relations between Iran and Israel became increasingly tense as the countries engaged in a series of proxy conflicts and covert operations against each other.
2006 War
During the 2006 Lebanon War, Iranian Revolutionary Guards (IRGC) were believed to have directly assisted Hezbollah fighters in their attacks on Israel. Multiple sources suggested that hundreds of Revolutionary Guard operatives participated in the firing of rockets into Israel during the war, and secured Hezbollah's long-range missiles. Revolutionary Guard operatives were allegedly seen operating openly at Hezbollah outposts during the war. In addition, Revolutionary Guard operatives were alleged to have supervised Hezbollah's attack on the INS Hanit with a C-802 anti-ship missile. The attack severely damaged the warship and killed four crewmen. It is alleged that between six and nine Revolutionary Guard operatives were killed by the Israeli military during the war. According to the Israeli media, their bodies were transferred to Syria and from there flown to Tehran. On 6 September 2007, the Israeli Air Force destroyed a suspected nuclear reactor in Syria, with ten North Koreans reportedly killed.
Evolving Iranian support to Hamas
During and immediately after the Gaza War, the Israeli Air Force, with the assistance of Israeli commandos, was reported to have allegedly carried out three airstrikes against Iranian arms being smuggled to Hamas through Sudan, as Iran launched an intensive effort to supply Hamas with weapons and ammunition. Israel hinted that it was behind the attacks. Two truck convoys were destroyed, and an arms-laden ship was sunk in the Red Sea.
On 4 November 2009, Israel captured a ship in the eastern Mediterranean Sea and its cargo of hundreds of tons of weapons allegedly bound from Iran to Hezbollah.
Proxy conflicts and sabotage
2010
In June 2010 Stuxnet, an advanced computer worm was discovered. It is believed that it had been developed by US and Israel to attack Iran's nuclear facilities. In a study conducted by ISIS it was estimated that Stuxnet might have damaged as many as 1,000 centrifuges (10% of all installed) in the Natanz enrichment plant. Other computer viruses and malware, including Duqu and Flame, were reportedly related to Stuxnet. Iran claims that its adversaries regularly engineer sales of faulty equipment and attacks by computer viruses to sabotage its nuclear program.
2011
On 15 March 2011, Israel seized a ship from Syria bringing Iranian weapons to Gaza. In addition, the Mossad was also suspected of being responsible for an explosion that reportedly damaged the nuclear facility at Isfahan. Iran denied that any explosion had occurred, but The Times reported damage to the nuclear plant based on satellite images, and quoted Israeli intelligence sources as saying that the blast indeed targeted a nuclear site, and was "no accident". Hours after the blast took place, Hezbollah fired two rockets into northern Israel. The Israel Defense Forces reacted by firing four artillery shells at the area from where the launch originated. It was speculated that the attack was ordered by Iran and Syria as a warning to Israel. The Israeli attack was reported to have killed 7 people, including foreign nationals. Another 12 people were injured, of whom 7 later died in hospital.
The Mossad was suspected of being behind an explosion at a Revolutionary Guard missile base in November 2011. The blast killed 17 Revolutionary Guard operatives, including General Hassan Moqaddam, described as a key figure in Iran's missile program. Israeli journalist Ron Ben-Yishai wrote that several lower-ranked Iranian missile experts had probably been previously killed in several explosions at various sites.