Why did the US attack Iran? Is the US at war? Here's what to know

March 1, 2026

The United States, in coordination with Israel, launched a large-scale military assault on Iran early Saturday morning that President Trump labeled "major combat operations," resulting in the death of Supreme Leader Ayatollah Ali Khamenei and hundreds of Iranian casualties across the country. Trump justified the strikes by citing Iran's refusal to abandon its nuclear program, historical grievances including the 1979 embassy takeover, and alleged threats from missile development, though this came just days after failed nuclear negotiations with Tehran. Iran retaliated by launching counterattacks against US military installations and Israel throughout the Middle East region.

Who is affected

Supreme Leader Ayatollah Ali Khamenei (killed)
Approximately 40 Iranian officials (killed)
Over 200 Iranian civilians killed and more than 700 injured across 24 of Iran's 31 provinces
108 people killed in a school explosion in southern Iran
One person killed and at least 20 wounded in Tel Aviv, Israel
One person killed in Abu Dhabi, UAE
US military personnel stationed at bases in Bahrain, Kuwait, Qatar, and UAE
Iranian civilians in the capital Tehran and other affected provinces
Congressional leaders (the "Gang of 8" notified ahead of strikes)
Residents of New York City and Los Angeles (placed on high alert)

What action is being taken

The US and Israel are conducting ongoing air raids and bombing operations against Iran (Trump warned bombing would continue throughout the week)
US aircraft carriers USS Gerald R Ford and USS Abraham Lincoln are deployed in the region
The US military has 12 ships in the Middle East with F-35 and F-22 fighter jets, refueling tankers, and surveillance aircraft conducting operations
Iran is launching counter-attacks with drones and missiles at Bahrain, Kuwait, Qatar, UAE, and Israel
New York City emergency management officials are taking "proactive steps" at "sensitive locations"
Los Angeles police have stepped up patrols
Iranian state TV has declared 40 days of mourning for Khamenei

Why it matters

This represents a major escalation in US-Iran tensions that transforms decades of proxy conflicts and covert operations into direct military confrontation between the two nations. The killing of Iran's Supreme Leader, who ruled for 35 years, creates a leadership vacuum in one of the Middle East's most influential powers and could destabilize the entire region. The operation raises critical constitutional questions about presidential war powers versus congressional authority to declare war, exposing deep partisan divisions that could have lasting implications for American democratic governance. The conflict also puts thousands of US troops stationed across the Middle East at immediate risk and threatens to draw regional allies into a wider war, while the potential for Iranian retaliation against the US homeland has cities on high alert.

What's next

Bombing operations are expected to continue throughout the week according to Trump's warning
Democrats are renewing calls for Congress to take up a war powers resolution to block the president's unilateral use of force
Iran has declared 40 days of mourning for Khamenei, suggesting a period during which Iran will need to address leadership succession

Read full article from source: BBC