I do believe it. I was born in Guyana, which is a diverse nation that has a long history of racial conflict, so I can speak to how these issues play out in other parts of the world. The question of creating unity out of diversity is not a problem which is unique to America.
I am also not sure why you would make bets on strangers. I am not against polygamy, although it’s not something I advocate for. It’s also very presumptive of you to assume that Nigerians and Sudanese do not care about the rights of women, when the fact is that there are activists in those countries who struggle for equal rights for women just as some activists in America struggle for equality of women in America. Not too long ago Sudan banned FGM. This was obviously done because people there care very deeply about the rights of women.
Civil rights are in fact global values. I know this because I was born outside of America and much of the work that I have done as an activist has been focused on international issues, particularly across Africa. Your argument is based on a concept of American exceptionalism which is fictitious. You also should spend more time engaging African Americans. Many of them are American by nationality, but do not feel connected to America or the culture. This is why so many African Americans have been moving to Ghana and other countries.