Explained | 'Sanctions, military pressure and more': Roots behind decades-long US-Iran conflict

Although not in the form of a full-fledged war, the conflict existed in various other forms over the past 5 decades -- a shadow war shaped by power imbalances, sanctions, accidents, and interventions that began long before the world started paying attention.

What the world is witnessing today across West Asia may look like the beginning of another long and unpredictable war. But the roots of this conflict was sown over five decades ago and ever since then, there hasn't been a pause in it. Although not in the form of a full-fledged war, the conflict existed in various other forms -- a shadow war shaped by power imbalances, sanctions, accidents, and interventions that began long before the world started paying attention.

For many in the US, the story starts in 1979, when Iranian students stormed the US Embassy in Tehran and took American personnel hostage. But in Iran, the roots run deeper: decades of Washington’s backing of the Shah, and later, its steadfast support for Iraq during the gruelling 1980–1988 Iran–Iraq War. That imbalance -- one superpower shaping the region from afar, and a smaller nation reacting under pressure, has defined the relationship ever since.

The first major phase of conflict unfolded during the 1980s “tanker war.” After Iraq attacked ships bound for Iranian ports, the US Navy expanded its presence, escorting reflagged Kuwaiti tankers and striking Iranian vessels. Tehran viewed this as a foreign military power entrenching itself along its shores.

The second phase emerged after the 2003 Iraq invasion under George W Bush, when US troops effectively surrounded Iran. In response, Tehran supported Iraqi militias like Asa'ib Ahl al-Haq, seeing them as leverage against a far stronger adversary.

The third phase came in the 2010s and 2020s. Though the two countries briefly found themselves aligned against ISIS, that cooperation collapsed when Donald Trump withdrew from the nuclear deal in 2017 and reimposed sanctions. Escalation followed: attacks on US facilities by Kataib Hizballah, and then the January 2020 drone strike that killed Iranian commander Qassem Soleimani and Iraqi leader Abu Mahdi al-Muhandis. Iran retaliated with missiles at Ain al-Asad Airbase.

Civilian tragedies

The conflict’s most painful moments have not been battlefield clashes, but civilian catastrophes.

In July 1988, the USS Vincennes shot down Iran Air Flight 655, killing all 290 people aboard. Washington called it a misidentification. Iranians saw it through a different lens: a well-armed superpower operating aggressively in their backyard with devastating consequences.

Iran, too, has made deadly mistakes under pressure. In January 2020, during a tense standoff with the US, the Islamic Revolutionary Guard Corps mistakenly downed Ukraine International Airlines Flight 752, killing 176 people.

Most recently, in February 2026, a US–Israeli missile struck a girls’ school in southern Iran, killing more than 150 civilians -- mostly children. For many Iranians, it felt like another reminder that they remain on the receiving end of a disproportionate conflict.

For many in Iran, today's escalation is part of a decades-long pattern: sanctions, military pressure, and a superpower deploying its strength across their region. The 2015 nuclear deal, which was championed by the then US President Barack Obama, was the closest the two sides came to breaking the cycle. Its collapse helped pave the way for the current crisis.

With inputs from agencies