Anti-war thought has become a much more dominant factor in global politics during the last half of the 20th century. Public anti-war protests have become a common outlet for anti-war feelings in recent years, often attracting hundreds of thousands of participants.
In practice, most of the largest anti-war movements have been orchestrated in opposition to wars led by the government of the United States. Anti-war sentiment in America reached a peak during the height of the Vietnam War and was rekindled to an extent in the months leading up to the 2003 invasion of Iraq. February 15, 2003 saw the biggest global protest movement ever against the predicted invasion of Iraq, with millions of participants worldwide.