The conflict that defines the Middle East – the history, challenges and upheavals in US-Iran relations

Relations between Iran and the United States are among the most turbulent and multi-layered conflicts in the history of modern international politics. Their dynamics have encompassed periods of close alliance, dramatic reversals, open hostility, indirect confrontations and attempts at diplomatic rapprochement. This conflict is rooted in conflicting geopolitical, ideological and economic interests, and its effects are felt not only in the Middle East but also in the global balance of power. To understand the dynamics between these two countries, it is necessary to trace over a century of history in their mutual relations, which have evolved from neutral cooperation into one of the most enduring disputes on the international stage.

The origins of US-Iranian relations date back to the 19th century, when Iran, then known as Persia, was under the influence of the imperial ambitions of Russia and Great Britain. During this period, the United States appeared as a neutral partner, unencumbered by colonial interests. Americans such as Arthur Millspaugh and Morgan Shuster served as advisers, helping to modernise the entire country. Their presence was seen as a symbol of integrity and professionalism, which helped to build a positive image of the US amongst Iranians. Relations remained cordial until the mid-20th century and grew particularly close after the Second World War, when Iran became a key element of the US strategy to contain the USSR. The US supported Tehran during the 1946 Azerbaijan crisis, and its diplomatic pressure led to the withdrawal of the Red Army from northern Iran. In the 1940s and 1950s, Washington viewed Iran as a key element for stability in the Middle East, investing in the development of infrastructure, education and administration, whilst Shah Mohammad Reza Pahlavi was regarded as a loyal ally.

After the war, however, Iranian dissatisfaction with British control over the country’s oil reserves grew. The Anglo-Iranian Oil Company, which controlled the majority of production, channelled its profits back to London, leaving Iranians feeling exploited and robbed. In 1951, Prime Minister Mohammad Mosaddegh nationalised the oil industry, a move that was met with strong disapproval from the UK and the US, which feared a loss of influence and the destabilisation of the region. Mosaddegh became a symbol of Iranian nationalism, the struggle for economic sovereignty and independence from more powerful nations. In 1953, the CIA and MI6 carried out Operation Ajax, which led to Mosaddegh’s overthrow and the restoration of the Shah to power. The coup d’état became one of the most controversial moments in the history of relations between the two countries and permanently instilled anti-American sentiment within Iranian society. This event remains in the collective memory of Iranians as a symbol of betrayal and the beginning of American domination. Following the coup, Iran signed the 1954 agreement, granting a 40 per cent stake in the oil industry to American, British and French companies. The Shah, supported politically and militarily by the US, launched an ambitious modernisation programme, known as the ‘White Revolution’. Although this brought about developments in infrastructure, education and women’s rights, it also exacerbated social inequalities and provoked resistance from conservative religious circles. The US became the guarantor of the Shah’s power, which, in the eyes of many Iranians, made it jointly responsible for political repression

In the 1960s and 1970s, cooperation between the two countries was extensive, particularly in the field of nuclear energy. In 1957, the US signed an agreement with Iran on the civilian use of nuclear energy as part of the ‘Atoms for Peace’ programme, supplying a research reactor and highly enriched fuel. As relations improved, Iran purchased American weapons, and the Shah was seen as a pillar of stability in the country and the region. At the same time, his authoritarian rule and the brutality of the security services were provoking growing public opposition. Criticism of the American presence in Iran was also mounting, both amongst the clergy and in left-wing circles. The US was seen as the guarantor and protector of a corrupt regime, which became one of the main factors leading to the Islamic Revolution.

In 1979, mass protests led to the overthrow of the Shah. Ayatollah Ruhollah Khomeini returned to the country and established the Islamic Republic of Iran, a state based on the principles of Shia theocracy. The new regime regarded the US as its main adversary, a symbol of ‘imperialism’ and a supporter of the deposed monarch. Anti-American rhetoric became one of the ideological cornerstones of the newly formed state. On 4 November 1979, Iranian students seized the US embassy in Tehran, taking 52 diplomats hostage. The crisis lasted 444 days and became one of the most traumatic events in US history. The attempt to free them, Operation Eagle Claw, ended in disaster. This event led to the final severance of diplomatic relations between the two countries and cemented their mutual hostility.

In the 1980s, the conflict entered a new phase, dominated by the Iran–Iraq War. The US, fearing the spread of the Islamic Revolution, provided Iraq with intelligence and military support. In the Persian Gulf, clashes took place between the US Navy and Iranian vessels, including during Operations ‘Nimble Archer’ and ‘Praying Mantis’. In 1988, the American warship USS Vincennes shot down an Iranian passenger aircraft, killing 290 people. This incident remains to this day one of the most painful episodes in the history of relations between the two countries. Paradoxically, in the mid-1980s, Ronald Reagan’s administration secretly sold arms to Iran in exchange for help in securing the release of hostages held by Hezbollah in Lebanon. The proceeds from these transactions were channelled to rebels in Nicaragua, sparking a massive political scandal in the US. The Iran-Contra affair demonstrated that, despite their official hostility, the two countries were capable of conducting behind-the-scenes negotiations.

Following the end of the Cold War, the US imposed extensive economic sanctions on Iran, accusing it of supporting terrorism and seeking to develop nuclear weapons. In 2002, President George W. Bush described Iran as part of the ‘axis of evil’, which deepened mutual hostility. At the same time, secret Iranian nuclear facilities were uncovered, triggering an international crisis. In the years that followed, Iran continued to develop its nuclear programme, arguing that it was for civilian purposes, whilst the US and its allies feared military ambitions. The economic sanctions weakened the Iranian economy but did not lead to a change in policy.

In 2015, Iran and six world powers signed the JCPOA, an agreement limiting Iran’s nuclear programme in exchange for the lifting of some sanctions. This was the most significant step towards the normalisation of relations since 1979. However, in 2018, Donald Trump’s administration withdrew the US from the agreement and reimposed sanctions, leading to an escalation of tensions and the resumption of uranium enrichment by Iran.

Between 2020 and 2024, tensions escalated following Iranian attacks on oil tankers in the Gulf of Oman, cyber-attacks on US infrastructure, and US strikes against Iranian militias in Iraq and Syria. The killing of General Qasem Soleimani in 2020 was one of the most significant escalations. In 2025 and 2026, a series of incidents and reciprocal attacks took place. In February 2026, the US and Israel carried out a joint operation against Iranian military installations, in which Iran’s supreme leader, Ali Khamenei, was killed. This was an unprecedented act which led to open war between the two countries. After three months of fighting, in June 2026, the US and Iran agreed to a ceasefire, brokered by Pakistan and Qatar. The memorandum provided for a 60-day de-escalation period and the start of talks on a lasting agreement. Although the conflict was not resolved, it was a sign that both sides recognised the costs of further escalation.

The sources of the conflict are multifaceted. Geopolitically, Iran views the US as a power that interferes in the region’s affairs and supports its adversaries – Israel, Saudi Arabia and Iraq. The US, for its part, fears Iranian expansion, support for organisations such as Hezbollah, and Tehran’s nuclear ambitions. Ideologically, the Islamic Revolution built Iran’s political identity on opposition to the West, whilst in the US, memories of the hostage crisis and Tehran’s anti-American rhetoric made it difficult to build trust. Economically, Iran’s energy resources have been a key element of the relationship from the outset. Control over oil was the reason behind the 1953 coup, and economic sanctions have become the US’s main tool for exerting pressure.

The history of Iran-US relations is a story of lost trust, conflicting interests and dramatic twists and turns. From the coup in 1953 to the war in 2026, the two countries have repeatedly found themselves on the brink of open conflict. Despite periodic attempts at dialogue, lasting normalisation would require a profound shift in the policies of both sides, both in terms of regional security and their approach to nuclear issues.