Iran, the United States and Israel: Why the Rivalry Endures

The rivalry between Iran, the United States and Israel is one of the longest-running conflicts in the Middle East. It grew out of the 1979 Iranian Revolution, which turned a close Western partner into an Islamic republic hostile to both countries, and it has since been shaped by Iran's nuclear programme, a network of allied armed groups, and a long series of covert attacks. In June 2025 the rivalry became open war for twelve days, and since 28 February 2026 the United States and Israel have been at war with Iran and its regional allies.^[16][19]

This Finepedia guide, updated in October 2026, explains how the three countries went from allies to enemies, why the nuclear question became central, how the proxy conflict works, and where diplomacy stands now. Contested claims are attributed to the side or source that makes them.

Key Facts

From Allies to Enemies

Iran and the West Before 1979

Relations between Iran and the United States were positive for much of the 20th century.^[1] That changed in Iranian memory with the coup of 19 August 1953, which overthrew Prime Minister Mohammad Mosaddegh and strengthened the rule of Shah Mohammad Reza Pahlavi.^[3] The coup was organised by the Central Intelligence Agency with help from Britain's MI6.^[1] A key motive was to protect British oil interests after Mosaddegh nationalised Iran's oil industry in 1951.^[3] An alliance between the Shah's government and the United States followed.^[1]

Iran under the Shah also had working ties with Israel. It was the second Muslim-majority country, after Turkey, to recognise Israel as a sovereign state.^[2] Israel saw Iran as a natural ally, a non-Arab power on the edge of the Arab world, in line with David Ben-Gurion's idea of an "alliance of the periphery".^[2]

The 1979 Revolution

The Iranian Revolution of 1979 overthrew the Pahlavi dynasty and replaced the monarchy with the Islamic Republic of Iran, led by the cleric Ruhollah Khomeini as supreme leader.^[4] Iran cut diplomatic ties with both the United States and Israel.^[19]

On 4 November 1979 students loyal to Khomeini stormed the US embassy in Tehran and took 66 Americans hostage. Fifty-two of them were held until 20 January 1981.^[5] The hostage-takers demanded that the United States hand over the Shah, who had been admitted for cancer treatment.^[5] The crisis ended with the Algiers Accords, in which the United States agreed, among other things, not to intervene in Iranian affairs.^[19] The two countries have had no formal diplomatic relations since 1980.^[1]

The 1980s

During the Iran–Iraq War the United States supported Iraq.^[19] In the same decade the Reagan administration secretly sold arms to Iran between 1981 and 1986, hoping in part to use the proceeds to fund the Contra rebels in Nicaragua. This became the Iran–Contra scandal.^[6]

Hezbollah was founded in Lebanon in 1982 by Shia clerics in close cooperation with Iran, primarily to fight the Israeli invasion of Lebanon.^[22] It became the most important of Iran's allied armed groups.

At sea, tensions turned violent in 1988. On 14 April the US frigate Samuel B. Roberts struck a mine, and on 18 April the United States attacked Iranian naval targets in Operation Praying Mantis.^[24] On 3 July 1988 the warship USS Vincennes shot down Iran Air Flight 655, an Airbus A300 flying from Bandar Abbas to Dubai over Iranian waters. All 290 people on board were killed.^[7]

Why the Rivalry Endures

The Nuclear Question

Iran's nuclear enrichment programme has been an international controversy for decades, with Israel and its allies seeking to prevent Iran from developing nuclear weapons.^[16] Iran's stated aim is a self-sufficient nuclear fuel cycle for power and medical isotopes, and it cites a legal right to peaceful technology under the Non-Proliferation Treaty.^[10] The worry for its rivals is that the same enrichment technology used for reactor fuel can, at higher levels, produce material for a bomb.

The Stuxnet computer worm, first uncovered on 17 June 2010, is believed to have caused substantial damage to Iran's programme after it was installed at the Natanz facility in 2009.^[11] Neither the United States nor Israel has openly admitted responsibility, but multiple news organisations have reported that it was built jointly by the two countries.^[11]

The Joint Comprehensive Plan of Action, or JCPOA, was finalised in Vienna on 14 July 2015 between Iran, the five permanent members of the UN Security Council, Germany and the European Union.^[12] Under it, Iran agreed to cut its stockpile of low-enriched uranium by 97%, from 10,000 kg to 300 kg, and limit enrichment to 3.67%, enough for civilian power but not weapons, in return for sanctions relief.^[12]

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In 2018 President Donald Trump withdrew the United States from the deal and imposed sanctions under a "maximum pressure" campaign.^[12] Iran then reduced its compliance and raised enrichment to 60%, just short of weapons grade of 90% and above.^[10] In September 2025 France, Britain and Germany triggered the deal's snapback mechanism, and UN sanctions were officially reimposed on 28 September 2025.^[12]

Proxies and the Axis of Resistance

The Axis of Resistance is an informal Iran-led military coalition across West Asia. It unites armed groups allied with Iran, mainly Shia Islamist organisations such as Hezbollah in Lebanon, the Islamic Resistance and Popular Mobilization Forces in Iraq, and the Houthis in Yemen.^[9] Syria was a key member until the fall of the Assad government in 2024.^[9]

For Israel and the United States, this network is a major threat; for Iran, it is a way to deter attack and project power without direct war. After the Gaza war began in 2023, the Houthis started firing missiles at Israel and attacking ships off Yemen in the Red Sea, saying they acted in solidarity with Palestinians.^[23]

Ideology and Regional Power

In 1979 Khomeini denounced Israel as a "Zionist regime" and the "Little Satan", and cut off relations; the United States was called the "Great Satan".^[2] The Israeli government, for its part, regards Iran as an existential threat because of its backing for armed groups across the region.^[2] Iran's rivals in the region include not only the United States and Israel but also Saudi Arabia and the United Arab Emirates.^[9] The rivalry is therefore also a contest over who shapes the Middle East's balance of power.

The Shadow War

For decades most fighting happened through proxies, sabotage and targeted killings rather than open war.^[8] The most prominent US action came on 3 January 2020, when an American drone strike ordered by President Trump killed Qasem Soleimani, commander of the Quds Force of Iran's Islamic Revolutionary Guard Corps, near Baghdad International Airport.^[13] Soleimani was considered the second most powerful person in Iran after Supreme Leader Ali Khamenei.^[13]

Direct Strikes in 2024

The shadow war broke into the open in 2024. On 1 April Israel bombed Iran's consulate in Damascus, killing two Iranian generals.^[14] On 13 April Iran and its allies launched drones, cruise missiles and ballistic missiles at Israel, Iran's first direct attack on Israel since the start of their proxy conflict.^[14]

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On 1 October 2024 Iran fired about 200 ballistic missiles at Israel, then the largest attack in their conflict.^[15] Iran said it was responding to Israel's killings of Hamas leader Ismail Haniyeh in Tehran, Hezbollah leader Hassan Nasrallah and IRGC general Abbas Nilforoushan.^[15]

The Twelve-Day War (June 2025)

On 13 June 2025 Israel launched surprise strikes on military and nuclear sites in Iran, killing military leaders, nuclear scientists and civilians.^[16] The day before, the International Atomic Energy Agency had declared Iran non-compliant with its nuclear obligations.^[16] Iran answered with more than 550 ballistic missiles and over 1,000 drones.^[16]

On 22 June the United States attacked the Fordow, Natanz and Isfahan nuclear sites in Operation Midnight Hammer, using fourteen GBU-57 "bunker buster" bombs dropped by B-2 stealth bombers and Tomahawk missiles fired from a submarine.^[17] President Trump said the sites were "completely and totally obliterated", but later reporting indicated that only Fordow had been "mostly destroyed", and a July 2025 Pentagon assessment found the programme was likely set back by around two years.^[17]

Iran fired missiles at a US base in Qatar, and on 24 June Israel and Iran agreed to a ceasefire under US pressure.^[16] Iran's death toll has been estimated at between 1,060 and 1,190.^[16] Iran suspended cooperation with the IAEA, saying the agency had passed information to Israel.^[16]

The 2026 War

Protests and the Road to War

On 28 December 2025 nationwide protests broke out in Iran amid a sharp fall in the rial, high inflation and shortages. They spread to more than 200 cities and became the largest uprising since 1979.^[18] The crackdown, reportedly ordered by Ali Khamenei and senior officials, left thousands of protesters dead.^[18] In January and February 2026 the United States carried out its largest military buildup in the region since the 2003 invasion of Iraq.^[19]

Strikes and Escalation

On 28 February 2026, during US–Iran talks on the nuclear programme, the United States and Israel launched hundreds of air strikes across Iran. The strikes killed Supreme Leader Ali Khamenei and several other officials.^[19] Khamenei, born in 1939, had led Iran since 1989, making him its longest-serving supreme leader.^[20] On 8 March his second son, Mojtaba Khamenei, was elected to replace him.^[19]

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The US side gave reasons including preventing an Iranian nuclear weapon and a response to the killing of protesters; critics called the attack a war of aggression in violation of international law.^[19] Iran responded with missile and drone attacks on Israel and US bases, attacked US allies in the region and blocked the Strait of Hormuz.^[19] Fighting between Israel and Hezbollah resumed two days after Khamenei's death. Israel began occupying southern Lebanon in March and launched large airstrikes across the country in April.^[19] After Iranian strikes on their territory, the United Arab Emirates, Saudi Arabia, Kuwait and Bahrain also attacked Iran and clashed with its Iraqi allies.^[19] In September an escalation by the Houthis in Yemen started a crisis in the Bab al-Mandab Strait, followed in October by a wave of drone and missile attacks on Saudi Arabia.^[19] The UN Secretary-General and several countries condemned the US–Israeli strikes, while the Security Council passed a resolution condemning Iran's retaliatory strikes on Gulf states.^[19]

Ceasefires That Did Not Hold

A two-week ceasefire from 8 April came under strain, and talks in Islamabad on 12 and 13 April, the highest-level US–Iran talks since 1979, failed. The United States then imposed its own naval blockade.^[19] A memorandum to end the war was signed in June, lifting the dual blockade, and on 28 June the two sides agreed to stop trading attacks.^[19] That deal collapsed on 8 July after Iran attacked commercial shipping in the Strait of Hormuz, and the two sides resumed trading attacks in early September.^[19]

The war has caused thousands of civilian and military casualties and the largest supply disruption in the history of the global oil market.^[19] As of October 2026 the US Department of Defense estimated its cost at $47.1 billion, and the Pentagon acknowledged 21 US fatalities and 865 injuries.^[19] In September 2026 a UN-commissioned fact-finding panel said there were "reasonable grounds" to believe the United States had committed war crimes during strikes in Iran.^[19]

The Strait of Hormuz and the World Economy

The Strait of Hormuz is the narrow sea lane between Iran and the Arabian Peninsula. During 2023 to 2025, about 20% of the world's liquefied natural gas and 25% of seaborne oil trade passed through it each year.^[25] More than 85% of the crude exported through the strait went to Asian markets, led by Japan, India, South Korea and China.^[25]

When Iran blocked the strait in 2026, shipping slowed to a standstill and about 150 freight ships, including oil tankers, were stalled.^[19] China and the European members of NATO rejected President Trump's call in March to help reopen it by force, and the United States began its own air campaign against Iranian vessels and drones in the strait.^[19] The disruption also hit natural gas, fertiliser, aviation and tourism, and pushed up inflation and living costs in the United States, according to Reuters reporting cited in the war's record.^[19] Because most of that oil goes to Asia, the strait links the conflict directly to fuel prices in countries such as India.^[25]

Where Diplomacy Stands (October 2026)

As of late October 2026, Gulf states were working on a multipart deal to stop the war from resuming. The plan would reopen the Strait of Hormuz within days of sanctions being lifted and have the Houthis withdraw substantial forces inside Yemen.^[21] Iran said it could shorten its proposal for reopening the strait from seven days after sanctions are lifted to four.^[21]

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The main gap is over the nuclear programme. European diplomats see letting UN inspectors back into Iran and into its bombed nuclear sites as a minimum condition for a breakthrough with President Trump, but Iran has so far refused and is focused on guarantees of sanctions relief.^[21] Oman's foreign minister, Badr Albusaidi, has backed a wider regional security plan that would include Iran and the Gulf states.^[21]

Key Figures

• 1953: year of the CIA- and MI6-organised coup against Mosaddegh.^[1][3]
• 52: US hostages held until 20 January 1981.^[5]
• 290: people killed when USS Vincennes shot down Iran Air Flight 655 in 1988.^[7]
• 3.67%: enrichment cap under the 2015 JCPOA.^[12]
• 60%: enrichment level Iran reached after the US left the deal.^[10]
• 550+: ballistic missiles Iran fired in the Twelve-Day War.^[16]
• 14: GBU-57 bombs used in Operation Midnight Hammer.^[17]
• 200+: Iranian cities reached by the 2025–2026 protests.^[18]
• 25%: share of seaborne oil trade that passed through the Strait of Hormuz in 2023 to 2025.^[25]
• $47.1 billion: US Defense Department estimate of the 2026 war's cost, as of October 2026.^[19]

Frequently Asked Questions

Why do Iran and the United States not have diplomatic relations?

Ties broke after the 1979 revolution and the seizure of the US embassy in Tehran. The two countries have had no formal diplomatic relations since 1980.^[1][5]

Were Iran and Israel ever allies?

Yes. Under the Shah, Iran recognised Israel and Israel saw it as a partner on the edge of the Arab world.^[2]

What was the JCPOA?

It was the 2015 deal that limited Iran's nuclear programme in return for sanctions relief. The United States withdrew in 2018, and UN sanctions were reimposed in September 2025.^[12]

Who leads Iran now?

Mojtaba Khamenei became supreme leader on 8 March 2026 after his father was killed in the opening strikes of the war.^[19]

See also

• The Israeli-Palestinian Conflict
• The India-China Border Dispute
• History of Human Civilization