Mandela and the Question of Violence

Ta-Nehisi Coates in Atlantic.com says "One should never lose sight of why America preaches nonviolence to some people while urging other people to arms."

In the shadow of our conversation, one sees a constant, indefatigable specter which has dogged us from birth. For the most of American history, very few of our institutions believed that black people were entitled to the rights of other Americans. Included in this is the right of self-defense. Nonviolence worked because it conceded that right in the pursuit of other rights. But one should never lose sight of the precise reasons why America preaches nonviolence to some people while urging other people to arms. 

http://www.theatlantic.com/politics/archive/2013/12/mandela-and-the-question-of-violence/282255/