For the US radical anti-war protest group, see A.N.S.W.E.R.

Formed in the wake of the September 11th attacks, on September 14, 2001, by Ramsey Clark and members of the International Action Center, ANSWER was one of the first organizations formed to protest the policies of the Bush administration. Its first major action was a September 29, 2001, "Anti-War, Anti-Racist" political rally and march in Washington, D.C., primarily in protest of the then-impending U.S. invasion of Afghanistanoun Subsequently the organization has organized rallies drawing crowds in the hundreds of thousands, according to their figures published on their websites. ANSWER characterizes itself as anti-imperialist, and its steering committee consists of socialists, Marxists, civil rights advocates, and left-wing progressive organizations from the Muslim, Arab, Palestinian, Filipino, Haitian, and Latin American communities. Many of ANSWER's leaders were members of Workers World Party (WWP) at the time of ANSWER's founding, and are current members of the Party for Socialism and Liberation (PSL), a Marxist-Leninist organization that formed in 2004.