Why Are Israel and Iran at War? A History of the Conflict (1979–2026)
A background guide to how two former partners became enemies, from the Shah to the open war that began on 28 February 2026.
1948 – 1979 — Allies under the Shah
For three decades, Israel and Iran were quiet partners. Imperial Iran under Mohammad Reza Shah Pahlavi was one of the few Muslim-majority states to recognise Israel de facto in 1950. The two countries traded oil, weapons and intelligence; Israeli engineers helped build infrastructure in Tehran and Iran shipped crude to the Haifa refinery via the Eilat–Ashkelon pipeline.
There was no ideological bond — both governments simply shared enemies in Nasser's Egypt, Ba'athist Iraq and the Soviet Union — but the relationship was deep enough that Israel maintained a permanent diplomatic mission in Tehran and Mossad cooperated closely with Iran's SAVAK.
February 1979 — The Islamic Revolution and the rupture
The Islamic Revolution that brought Ayatollah Ruhollah Khomeini to power in February 1979 inverted Iran's foreign policy overnight. Khomeini called Israel the 'Little Satan' (with the United States as the 'Great Satan'), severed diplomatic ties, handed the Israeli embassy in Tehran to the Palestine Liberation Organisation, and made support for the Palestinian cause a pillar of the new Islamic Republic's identity.
This is the moment most historians treat as the start of the Iran–Israel conflict. The hostility was framed in religious and revolutionary terms, but its strategic logic was older: an Iran that no longer needed Israel as a counterweight to its Arab neighbours had no reason to pretend the relationship was anything but adversarial.
1982 – 2000 — Hezbollah and the proxy doctrine
When Israel invaded Lebanon in 1982 to expel the PLO, Iran's Revolutionary Guard Corps (IRGC) deployed to the Bekaa Valley and helped found Hezbollah out of fragmented Shia militias. This was the birth of Iran's signature strategy: rather than confront Israel directly, project power through armed non-state allies on Israel's borders.
Over the next two decades Hezbollah grew into the most heavily armed non-state military force in the world, fighting an 18-year insurgency that pushed Israel out of southern Lebanon in 2000. For Tehran it was proof that the proxy model worked.
2002 – 2015 — The nuclear file and the shadow war
Revelations in 2002 about a covert Iranian uranium-enrichment site at Natanz turned the conflict into a nuclear standoff. Israeli prime ministers from Ariel Sharon onward declared an Iranian bomb an existential threat and Israel began a campaign of sabotage, cyber-attacks (including the Stuxnet worm jointly developed with the United States), and the assassination of Iranian nuclear scientists.
Iran retaliated through proxies and intelligence operations, while accelerating enrichment. The 2015 Joint Comprehensive Plan of Action (JCPOA) capped Iran's programme in exchange for sanctions relief — but Israel publicly opposed the deal, arguing it merely postponed an inevitable confrontation.
2011 – 2020 — Syria, the land bridge, and the war between wars
The Syrian civil war became the conflict's main proving ground. Iran sent IRGC officers, Hezbollah fighters and Iraqi and Afghan militias to save Bashar al-Assad's government, in exchange for a 'land bridge' from Tehran to the Mediterranean. Israel responded with thousands of airstrikes on Iranian weapons shipments and IRGC infrastructure — what Israeli generals called the 'war between wars'.
By 2020, Iran's so-called Axis of Resistance — Hezbollah in Lebanon, militias in Syria and Iraq, Hamas and Islamic Jihad in Gaza, the Houthis in Yemen — encircled Israel on every front.
2018 – 2022 — Maximum pressure and the JCPOA collapse
Donald Trump withdrew the United States from the JCPOA in 2018 and reimposed crushing sanctions. Iran responded by gradually breaking the nuclear deal's limits, enriching uranium first to 20%, then 60%, levels with no civilian justification. Tankers were mined in the Gulf of Oman, drones struck Saudi oil facilities at Abqaiq, and Iranian general Qassem Soleimani was killed by a US drone strike in Baghdad in January 2020.
Israel intensified covert operations inside Iran, including the 2020 assassination of nuclear scientist Mohsen Fakhrizadeh and a fire at the Natanz centrifuge hall in 2021.
October 2023 — October 7 and the year of escalation
The Hamas attack of 7 October 2023 — the deadliest day for Jews since the Holocaust — triggered the longest and most destructive war in Gaza's history. Within hours Hezbollah opened a second front in northern Israel, the Houthis began attacking Red Sea shipping, and Iraqi militias struck US bases. The conflict that had been simmering for forty years was now multi-front and continuous.
April – October 2024 — From shadow war to open strikes
An Israeli airstrike on the Iranian consulate annex in Damascus in April 2024 killed senior IRGC commanders. Iran responded with the first direct attack on Israel from Iranian soil — more than 300 drones and missiles, the vast majority intercepted. Israel struck back with a limited strike near Isfahan.
In October 2024 Iran launched a much larger ballistic-missile barrage after Israel killed Hezbollah leader Hassan Nasrallah; Israel retaliated with strikes on Iranian air-defence and missile-production sites. The taboo on direct state-to-state attacks was gone.
2025 — The collapse of the proxy belt
Through 2025 the Axis of Resistance unravelled. Hezbollah's command was decimated, Assad fell in Damascus in December 2024 cutting the land bridge, and Hamas was reduced to insurgency. Iran's deterrent — built on the threat of proxies opening multiple fronts — no longer functioned. Tehran's nuclear programme accelerated, with the IAEA reporting weapons-grade enrichment for the first time.
February 2026 — The open war
On 28 February 2026 Israel launched a large-scale air and missile campaign against Iranian nuclear, missile and command sites — the operation IranWar.info has tracked from day one. Iran answered with sustained missile and drone attacks on Israeli cities, infrastructure and US bases in the Gulf. The conflict that began as ideological hostility in 1979 had finally become a direct war between the two states.
Common questions
Who started the Iran–Israel war?
There is no single starting date everyone agrees on. The diplomatic break came from Iran's side in 1979 when the new Islamic Republic cut ties and adopted hostility to Israel as state policy. The first direct state-on-state military strikes were Iran's drone-and-missile salvo in April 2024, which itself responded to an Israeli strike on the Iranian consulate compound in Damascus. The full-scale open war began on 28 February 2026 when Israel launched its strategic campaign against Iranian nuclear and missile infrastructure.
Why does Iran hate Israel?
The hostility is ideological, religious and strategic. Ideologically the 1979 revolution defined the Islamic Republic in opposition to the United States and Israel. Religiously Iran's clerical leadership frames support for the Palestinians and control of Jerusalem as a Muslim obligation. Strategically, opposition to Israel gives Tehran legitimacy across the Sunni Arab street and justifies the network of proxy forces that project Iranian power beyond its borders.
Have Iran and Israel always been enemies?
No. From 1948 until 1979 Imperial Iran under the Shah was a quiet partner of Israel, trading oil for weapons and intelligence. The two states only became enemies after the Islamic Revolution.
What is the Axis of Resistance?
It is the name Iran uses for the network of allied armed groups it funds, arms and trains: Hezbollah in Lebanon, Hamas and Palestinian Islamic Jihad in Gaza, Shia militias in Iraq and Syria, and the Houthi movement in Yemen. The doctrine, built since the 1980s, is to confront Israel through proxies rather than direct attack.
Is the Iran–Israel conflict about religion?
Partly. Israel is a Jewish state and Iran is a Shia Islamic theocracy, and the conflict is wrapped in religious language on both sides. But the substance — territory, the Palestinian question, the balance of power in the Middle East, nuclear weapons, oil routes — is overwhelmingly strategic.