As America debates action in Syria’s civil war, a new film documents boxer Muhammad Ali’s refusal to serve in Vietnam during the late 1960s.

The documentary, entitled The Trials of Muhammad Ali, highlights Ali’s resilience to his faith and a fundamental opposition to warfare prevalent today. It also spotlights his rise to the world heavyweight title at just 22 and subsequent devotion to the Nation of Islam.

A leader in the Black power movement, Ali forgoes enlistment in the military due to his religious doctrine and conflicting socio-political values. The response, as seen in the film, becomes one of his greatest hurdles outside the boxing ring.