Why did the United States and Israel go to war with Iran in 2026?

The war began on 28 February 2026, when the United States and Israel launched large-scale strikes on Iran. The American operation was codenamed Operation Epic Fury.

The core issue was Iran’s nuclear programme. Washington and Israel had demanded that Iran stop all uranium enrichment, which they saw as a path to nuclear weapons. Iran has always insisted its programme is peaceful and that it has the right to enrich uranium for civilian use. Talks failed, and tensions had already been high since a short war between Israel and Iran in June 2025, often called the Twelve-Day War.

The opening strikes targeted nuclear sites, missile facilities and military leadership. Iran’s Supreme Leader, Ayatollah Ali Khamenei, was killed, which was a massive shock both inside Iran and across the region.

Iran responded by firing waves of ballistic missiles at Israel and at US bases in the Gulf, and by effectively closing the Strait of Hormuz to many ships. Groups allied with Iran, including Hezbollah in Lebanon and the Houthis in Yemen, also joined in.

Supporters of the strikes argue that a nuclear-armed Iran would have been far more dangerous for the region and the world. Critics argue that the war was launched without a clear end plan, has caused huge civilian suffering and economic damage, and may push Iran further towards wanting a bomb. The debate is still very much alive, and the war played a large part in the 2026 US midterm results.