Nationalism fido

I big argument started in my mind few days back when in an informal discussion one of my colleague said, "the idea of nationalism is waste, how old it is, not even a few decades?". The discussion ended then and there itself but it gave me a point to think about, which I also agreed lately. Our school old pledge of...all Indians are brothers and sisters, isn't giving us a foundation for the the wall which we create in life later towards the rest of world and slowly that tendency makes us to make some more walls for insiders. It's OK that some are brothers and sisters but why aren't others. The crop of most of the terrorism across world have grown over the same soil of intellectual partitioning in our mind on the name of nationalism. Do we really need to be classified as a nation or a region or so...isn't it true that whatever, wherever we are we always like to relate ourselves with the root and the idea of bounding people from moving across globe is against humanity. In fact, any idea which allows people to differentiate themselves from other people is waste, either its religion, area, race, color or the nation itself. Only true thing which works is humanity which we really need in all of us across these thick walls.