Thousands of Americans gathered across the United States on Saturday to protest after news spread that Iran’s supreme leader, Ali Khamenei, had been killed in US and Israeli airstrikes in Tehran. Demonstrators voiced strong opposition to US military involvement in the region, appearing outside the White House, in New York’s Times Square, and in cities nationwide. Many protesters criticized the strikes as unauthorized by Congress. “No president can attack another country without approval,” said Sue Johnson, a participant in New York. She added that the action reflected impatience and unilateral decision-making by the Trump administration. A sense of frustration over US foreign policy shaped the gatherings. The Trump administration’s past actions, including the capture of Venezuelan president Nicolás Maduro, contributed to growing concern among activists that military decisions are often made without public oversight. Scores of protests were organized by a coalition of left-leaning groups, including American Muslims for Palestine, the People’s Forum, CodePink, the Black Alliance for Peace, and the Democratic Socialists of America. Demonstrations were planned in major cities such as Atlanta, Boston, Chicago, Denver, Las Vegas, Los Angeles, Miami, and Minneapolis, with smaller gatherings scheduled in Albany, Chattanooga, Decorah, Gainesville, and Springfield. Organizers described the airstrikes as an illegal act of war. Their statement warned that the attacks “threaten unthinkable death and destruction” and stressed that citizens reject involvement in another prolonged conflict. New York’s mayor, Zohran Mamdani, aligned with Democratic Socialists of America, called the strikes “a catastrophic escalation in an illegal war of aggression.” He emphasized that bombing cities and killing civilians could ignite a new theater of conflict that Americans do not support. The American Civil Liberties Union and several lawmakers urged Congress to intervene, highlighting the constitutional requirement that military action must receive legislative approval. The ACLU cited historical precedents, from Vietnam to Afghanistan, noting that past conflicts reinforce the need for congressional oversight before engaging in armed conflict abroad. Some protesters stressed that opposition to the airstrikes did not equate to support for the Iranian regime. Willie Cotton, 48, from Brooklyn, said he opposed US bombing despite concerns about Iran’s nuclear ambitions. Cotton noted that the US often enters conflicts for its own economic and political interests, rather than to assist local populations. Cotton, a member of the Socialist Workers Party, also acknowledged Israel’s right to defend itself following attacks by Hamas but emphasized that US actions in Iran served global strategic goals rather than self-defense. Heightened security accompanied the demonstrations. FBI counterterrorism and counterintelligence teams were placed on elevated alert, and Homeland Security Secretary Kristi Noem said federal authorities were coordinating to monitor potential threats. Despite security measures, protesters continued to voice their concerns. Jacqueline, handing out “Stop the War on Iran!” signs, said that even if the protests did not prevent military action, they allowed Americans to express opposition to endless Middle East wars. Healthcare worker Christina Perez, 44, joined the protests in Times Square to oppose the Trump administration broadly. She described waking up to the news of the strikes as another example of unchecked presidential power. “We are constantly distracted from domestic issues while resources are funneled into war,” she said. The demonstrations highlight widespread public unease over unilateral military actions and emphasize a call for Congress to reclaim authority over decisions that could lead to significant international conflict. Protesters across the nation remain determined to make their voices heard in opposition to what they view as reckless and unauthorized military action.