Breaking: the rest of the world does not necessarily have to be aware of, nor give a flying fuck about, muhrica's sensitivities.
It's not that they don't have to be aware of, and it certainly isn't that it is okay to not give a flying fuck about it, it is more about taking into account the world's ignorance of America's sensitivites.
For example: Some people act like there is something inherently racist or offensive about blacking your face. In other words, they should instinctively know what they are doing is wrong. However, I don't think it is so obvious.
Lets say there was a tribe in Papa New Guinea who had very little contact with the outside world. One day a white man entered their territory with medicine and technology from the West. The tribe saw this man as coming from the heavens. Once the man had left, the tribe decided that each year they would celebrate and pay tribute to the great white man, whom they revered, by painting their face white.
Now, it that context I find it hard to believe anyone would see the act of painting their face white as being inherently racist. Context matters.
The way I see it then, is blackface to a certain degree is contingent on American history; the history of slavery, oppression and so on. I don't think it is necessarily obvious to people that what they are doing is offensive. They may see it as a tribute. In fact I am sure some people do it for that reason.
I'm not saying you shouldn't criticise it, or try to make people aware, just that at least take into account people's ignorance of it.