I ain't got no quarrel with them Vietcong

No, I am not going 10,000 miles to help murder, kill, and burn other people to simply help continue the domination of white slavemasters over dark people the world over. This is the day and age when such evil injustice must come to an end.
Image courtesy of Wiki.

More on Ali and the US opposition to War Opposers, including popular, black ones at a time when war was more popular than US citizens:

In 1964, Ali failed the U.S. Armed Forces qualifying test because his writing and spelling skills were sub-par. However, in early 1966, the tests were revised and Ali was reclassified as 1A.^[10] This classification meant he was now eligible for the draft and induction into the U.S. Army during a time when the United States was involved in the Vietnam War. When notified of this status, he declared that he would refuse to serve in the United States Army and publicly considered himself a conscientious objector.^[10] Ali stated: "War is against the teachings of the Holy Qur'an. I'm not trying to dodge the draft. We are not supposed to take part in no wars unless declared by Allah or The Messenger. We don't take part in Christian wars or wars of any unbelievers." He famously said in 1966: "I ain't got no quarrel with them Viet Congs..."

Widespread protests against the Vietnam War had not yet begun, but with that one phrase, Ali articulated the reason to oppose the war for a generation of young Americans, and his words served as a touchstone for the racial and antiwar upheavals that would rock the 1960s. Ali's example inspired Martin Luther King, Jr. – who had been reluctant to alienate the Johnson Administration and its support of the civil rights agenda – to voice his own opposition to the war for the first time.^[62]

Rare for a heavyweight boxing champion in those days, Ali spoke at Howard University, where he gave his popular "Black Is Best" speech to 4,000 cheering students and community intellectuals after he was invited to speak by sociology professor Nathan Hare on behalf of the Black Power Committee, a student protest group.^[63][64]

Appearing shortly thereafter for his scheduled induction into the U.S. Armed Forces on April 28, 1967 in Houston, he refused three times to step forward at the call of his name. An officer warned him he was committing a felony punishable by five years in prison and a fine of $10,000. Once more, Ali refused to budge when his name was called. As a result, he was arrested and on the same day the New York State Athletic Commission suspended his boxing license and stripped him of his title. Other boxing commissions followed suit. Ali would not be able to obtain a license to box in any state for over three years.^[65]

At the trial on June 20, 1967, after only 21 minutes of deliberation, the jury found Ali guilty.^[10] After a Court of Appeals upheld the conviction, the case went to the U.S. Supreme Court. During this time, the public began turning against the war and support for Ali began to grow. Ali supported himself by speaking at colleges and universities across the country, where opposition to the war was especially strong. On June 28, 1971, the Supreme Court reversed his conviction for refusing induction by unanimous decision in Clay v. United States.^[10] The decision was not based on, nor did it address, the merits of Clay's/Ali's claims per se; rather, the government's failure to specify which claims were rejected and which were sustained, constituted the grounds upon which the Court reversed the conviction.^[66]