Can There Be World Citizenship

In the article "Can There Be World Citizenship" by Elise Boulding, the author talks about how she is striving for a more peaceful world. A world that is free of war, racism, etc., and she believes that all of this would be possible if the United Nations could do a better job of uniting the countries of this world. Also, she talks about the theory of the melting pot and how she believes it will happen basically letting there be only one common race on the planet. Boulding believes that with all of these pieces being put into place that a World citizenship would be possible. I disagree with what the author believes, and that there can't be a World citizenship. I think that it wouldn't be possible to have this because I don't think all the nations around the World would be free to just drop their borders and let anyone come in and out of the country with no issues. Also, if everyone were free to go anywhere they want and there wasn't any war, I feel like eventually a person or group would get power hungry and try to take over. This would eventually just lead back to where we are right now with new countries starting to pop up. The kind of greed and self think, reminds me of the "Generation Me" and "The Why-Worry Generation" articles, both articles talked about this generation being very selfish and always trying to help yourself out, and this type of thinking is part of what I think would make it impossible to have a world citizenship for everyone.