Seven decades of US regime change efforts: What have they achieved?

More than seven decades after the United States helped to overthrow Iran’s elected prime minister, Mohammad Mosaddegh, in 1953, the two countries are again locking horns.

The ongoing war between Washington and Tehran began when the US and Israel launched strikes across Iran on February 28, claiming Tehran was on the cusp of acquiring nuclear weapons.

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The war has been marked by fighting across the region, including Iranian retaliatory attacks on Gulf states. The conflict has also spilled into Lebanon, where Israel says it is targeting strongholds of the Iran-backed group Hezbollah, and Yemen, where the Iran-backed Houthis are currently targeting Saudi-linked ships in the Red Sea. The conflict has upended global energy markets, with the closure of the critical Strait of Hormuz, and progress towards a peace deal has stalled.

The US-Israel war on Iran is just the latest chapter in a US-Iran relationship that has been shaped by coups, covert operations, sanctions, military confrontations and brief, yet unsuccessful, attempts at diplomacy.

Since Iran’s 1979 Islamic revolution, led by former Supreme Leader Ruhollah Khomeini, overthrew the US-backed Shah Mohammed Reza Pahlavi, Washington has repeatedly sought to weaken the government in Tehran.

However, Iran is not an isolated case. From Guatemala and Cuba to Chile and Venezuela, the US has repeatedly intervened over the years against governments it considered hostile to its interests.

What have those efforts resulted in – and what lessons might they hold for Washington now?

How the US helped restore the shah to power in 1953

In 1953, the US’s Central Intelligence Agency (CIA) worked with Britain to overthrow Iran’s democratically elected Prime Minister Mohammad Mosaddegh after he nationalised the Anglo-Iranian Oil Company, something the Western powers saw as going against their interests. Mosaddegh had been in power since 1951.

The coup restored the shah, Pahlavi, to power. Iran’s last shah had first taken the reins of the country in 1941 during World War II, after his father, Reza Shah, was forced to abdicate the throne following an invasion by British and Soviet forces.

The Allies in the war were afraid of Reza Shah’s ties to Nazi Germany, which was its largest trading partner at the time, while also being interested in controlling Iran’s land and rail routes to bolster their own war efforts.

Following the coup against Mosaddegh in 1953, Washington and Tehran, under Pahlavi, were close allies for the next quarter century.

The US supported the shah, even helping Iran develop a civilian nuclear programme. In 1957, the two countries signed a nuclear cooperation agreement under US President Dwight Eisenhower’s “Atoms for Peace” initiative. A decade later, Washington supplied Iran with a nuclear reactor and uranium.

How the US-backed regime change in Iran backfired

Over time, the shah’s increasingly authoritarian rule fuelled opposition. In 1979, mass protests forced him from power, and former Supreme Leader Khomeini returned from exile to found the Islamic Republic.

The relationship between Washington and Iran soured, turning Iran from a close ally of the US into one of its principal adversaries.

On November 4, 1979, Iranian students seized the US Embassy and held 52 Americans hostage for 444 days, prompting Washington to cut diplomatic ties and impose sanctions on Tehran.

During the Iran-Iraq War in the 1980s, the US backed Iraq, and Iran also faced direct military confrontation with US forces.

Over the following decade, the US tightened sanctions further, citing Iran’s nuclear activities and its support for armed groups in the region, including Hamas in Gaza and Hezbollah in Lebanon.

Following the events of September 11, US President George W Bush labelled Iran part of an “axis of evil”, despite earlier cooperation between Washington and Tehran against the Taliban and al-Qaeda. Then, after several years of heightened tension, the election of US President Barack Obama saw a rare shift towards diplomacy.

The 2015 Joint Comprehensive Plan of Action (JCPOA) was a nuclear deal, negotiated between Iran and the US alongside other major world economies, including the United Kingdom, France and China. It restricted Iran’s nuclear activities in return for sanctions relief. The deal was short-lived, however. US President Donald Trump withdrew the US from the agreement during his first term in the White House in 2018 and restored sanctions. One year later, Iran began to enrich uranium beyond the limits it had agreed to in the deal, eventually building an estimated stock of 440kg (970 pounds) of highly enriched uranium.

In 2025, following his return to the White House for his second term, Trump proposed new nuclear talks with Iran, and negotiations began via mediators in Oman. But those talks collapsed when Israel launched attacks across Iran, in what became known as the 12-day war. The US subsequently joined the war, striking three nuclear facilities.

How the US tried regime change – again – in Iran

On February 28 this year, the US and Israel again launched strikes on Iran – once again in the middle of talks. One of the central aims of the war, Trump said, was regime change in Tehran. He framed this as “freedom for the people”.

“When we are finished, take over your government. It will be yours to take,” he said the day the war began.

That aim failed. While Supreme Leader Ayatollah Ali Khamenei and several senior leadership figures were killed in the initial strikes, they were quickly replaced by other clerical leaders, including the new Supreme Leader Mojtaba Khamenei, the son of Ali. The government in Tehran remains in place and, according to many observers, has strengthened its grip over the country’s affairs.

As a result of the US-Israeli strikes, thousands of people have been killed in Iran, with more killed in retaliatory strikes across the wider region. Shortly after the war began, the Lebanese armed group Hezbollah, which is backed by Iran, began firing rockets into northern Israel in retaliation for the killing of the supreme leader. This triggered near-daily strikes by Israel and its occupation of around one-fifth of Lebanon. Thousands of people have died there, while more than one million people have been displaced from their homes as Israel seeks to create a massive “buffer zone” between its territory and Hezbollah fighters.

The US president has since denied he was ever trying to achieve regime change in Iran, saying in June that he “never cared for regime change”. “I’ve watched regime changes for years; they never work,” Trump said.

Where else has the US attempted to force regime change in the Middle East and Afghanistan?

US intervention elsewhere in the region has also resulted in enormous human and financial costs.

In 2003, Washington and its allies invaded Iraq, seeking to remove Saddam Hussein, who they claimed had weapons of mass destruction (WMD). While Hussein was ultimately removed from power, no stockpiles of WMDs were found in later searches.

Hussein was executed by hanging in Baghdad after being convicted of crimes against humanity.

To achieve that, however, according to the Watson Institute of International and Public Affairs at Brown University, about 315,000 people were directly killed during the US conflict in Iraq.

In US-led conflicts since 2001 in Afghanistan, Pakistan, Iraq, Syria, Yemen and other conflict areas, about 940,000 people have been killed. Including deaths indirectly linked to war through disease, hunger and loss of healthcare, the estimated toll rises to 4.5-4.7 million, the institute has calculated.

The financial cost of US interventions in the Middle East specifically has been enormous. The US spent an estimated $5.8 trillion on more than two decades of war there, with another $2.2 trillion projected for veterans’ care over the following 30 years.

While US and allied forces successfully toppled the Taliban in Afghanistan in 2001 and maintained a presence there for 20 years in support of a civilian government, the Taliban swept in and retook power as soon as US forces withdrew from the country in 2021.

In Libya, US and Western military intervention in 2011 resulted in the removal of long-standing leader Muammar Gaddafi. The US initially led an international military operation authorised by the UN Security Council to protect civilians from forces loyal to Gaddafi.

The US then transferred command to NATO in March 2011, while continuing to provide key military capabilities, including surveillance and armed drones.

Since the overthrow of Gaddafi, Libya has struggled with political fragmentation, rival governments and armed groups competing for power. Years of fighting between factions culminated in a United Nations-backed ceasefire in 2020, but the country remains divided between competing institutions and military centres of power.

Washington is currently involved in efforts to broker an initiative aimed at ending the country’s institutional divide and bringing its competing executive authorities under a unified government.

What is the US’s history of intervention elsewhere in the world?

During the US-Soviet Cold War from 1945 to 1991, Washington backed or supported operations against elected left-wing governments across Latin America and the Caribbean – largely in an attempt to safeguard its own financial interests in those countries.

In 1954, the CIA helped overthrow Guatemala’s elected President Jacobo Arbenz after his government sought to nationalise land and pursued policies Washington viewed as increasingly socialist and against US interests. A civil war followed, lasting from 1960 to 1996.

In Cuba, the CIA trained Cuban exiles for an invasion aimed at removing leader Fidel Castro. The 1961 Bay of Pigs invasion failed when Cuban forces defeated the attackers.

The US backed anti-communist forces and politicians in Brazil, leading to a 1964 military coup that removed President Joao Goulart. Similar intervention took place in Ecuador and Bolivia.

In Chile, the CIA funded efforts against elected socialist President Salvador Allende, whose plans included nationalising copper companies owned by US companies. A 1973 military coup propelled General Augusto Pinochet to power for 17 years.

During Pinochet’s rule, more than 3,000 people were killed, while tens of thousands more were tortured or imprisoned. Around 1,400 people went missing as a result of forced disappearances, while at least 200,000 Chileans were exiled.

The US also invaded Grenada in 1983 and Panama in 1989, removing governments that Washington opposed.

Following the September 11 attacks on New York City, the US invaded Afghanistan in 2001 with the aim of dismantling al-Qaeda and removing the Taliban. The US occupied Afghanistan until 2021, after the Taliban retook the country in a lightning offensive.

According to the Watson Institute, the Afghanistan war and related conflict in Pakistan caused an estimated 243,000 direct deaths.

In January 2026, former Venezuelan President Nicolas Maduro and his wife Cilia Flores were abducted in a US military operation, after long-standing tensions between Washington and Caracas finally boiled over.

The Venezuelan presidency has since been filled by interim President Delcy Rodriguez, who has aligned the country more closely with US interests, which include control over the country’s oil industry.

Since Maduro’s abduction, Trump has promised US investment in Venezuela’s oilfields and infrastructure. Earlier this year, Washington lifted some sanctions on the country’s oil industry, making it easier for US companies to sell its crude oil.

Has the US learned any lessons?

In Iran, the US has repeatedly succeeded in changing Iran’s immediate political trajectory without being able to control the consequences, Andreas Krieg, associate professor at King’s College London, told Al Jazeera.

“The 1953 coup removed Mossadegh and preserved the Shah, but it also permanently associated the monarchy with Western intervention,” Krieg said.

US support for the Shah transformed anti-Americanism from merely being one strand of Iranian politics into a core component of the revolutionary coalition that overthrew him in 1979, Krieg said, noting, “In that sense, 1953 succeeded operationally and failed historically.”

Similarly, Krieg said, the US invasion of Iraq removed Saddam Hussein, Iran’s main regional counterweight, and “inadvertently created the political space in Iraq through which the IRGC built much of its post-2003 regional network”.

The “real lesson” from the past 70 years, Krieg said, should be about “strategic discipline”.

“The US has to distinguish between degrading specific Iranian capabilities and trying to redesign the Iranian political system,” he noted. “That is where the historical record should make Washington extremely cautious. In Iran, the United States has repeatedly discovered that removing one strategic problem can create a much larger one.”

Negar Mortavezi, senior fellow at the US-based Center for International Policy, said the consequences of US intervention in the Middle East have frequently been devastating.

“From the 1953 coup in Iran to regime-change wars and interventions across the Middle East, the US record is one of mayhem, instability and insecurity,” she said.

In Iran, the coup “crushed a democratic movement, consolidated authoritarian rule and laid the foundations for the deep anti-American sentiment that still shapes the relationship today”, Mortavezi added.

Across the region, she said, repeated US efforts to remove governments and engineer political outcomes have devastated states, empowered armed groups, displaced millions and produced consequences Washington neither anticipated nor could control.

“The central lesson should be clear: destroying a government is far easier than controlling what follows,” said Mortavezi. “Yet Washington has repeatedly confused military power with political control and regime removal with victory. Seven decades later, the same assumptions persist: that the United States can impose its preferred order from outside, that societies will respond as Washington expects, and that the consequences can be contained. The tactics may change, but the mistake remains the same.”

Reporting originally appeared via Al Jazeera. Read the full source for additional context.