Popular modern peaceful movements led by people such as Martin Luther King in the US and Ghandi in colonial India were parallel backed by violent groups such as the Black Panthers in the US and a bunch of small and very active violent groups in India.

Keep in mind with King (I’m not so studied up on Gandhi), optics played a big role. You had squeaky clean pillars of the community and schoolchildren being attacked by police dogs, hoses, and baton wielding police for daring to ask for equality. The US actually had decent journalism back then so they looked horrible on the world stage as the US was positioning itself as the leader of a free world. America’s arm was twisted into giving black people nominal rights with token representation while surreptitiously undermining both.

I’m not so sure the threat of armed black people made the government acquiesce. The state loves nothing more than a pretext for violence.