How to confront ethnocentrism?

My today's – or tonight's – thesis, to be defended in more detail later: Ethnocentrism cannot be refuted efficiently by oversimplifying it. The nationalist or ethnocentrist argument often begins with the sentence "I am not a racist..." (or, as in a Monty Python sketch, "I am not a racialist! But..."). In a certain sense, I tend to accept that claim, even though I know how easy it would be just to smirk at it. I tend to accept it because the concept of racism has become void of all precise content [later: that's rubbish]: as far as I know, racism used to be connected with a certain biologism and a belief in substantial differences between "races". No one seriously believes in racism any longer, in that sense, or at least professes such belief publicly (although there are notable exceptions to prove this rule). Ethnocentrism and nationalism need not even signify a belief in the intrinsic superiority of one's own nation or ethnic group. Rather, they seem to be founded on a certain notion of cultural "rootedness" that can very well subscribe to the idea of equality of different nations and ethnicities – a belief in a homestead, fatherland that is the best place for any nation to live their lives. A certain apparently rational myth of autochtony and an argument for monoculturalism...