I don't know why the Karim Karim reading in particular got me on this train of thought-- there are surely hundreds of scholars who have asserted something along the lines of:
"the roots of the contemporary global system of nation states are to be found in colonialism," as he does in "Chapter 24: Reviewing the 'National' in International communication."
But all I can think as I read that sentence is "ok, sure, but can't you replace 'colonialism' with 'tribalism'?" Groups of human beings have been banding together and fighting each other for territory, resources and power pretty much since we started hunting and gathering, right? Even when tribes lived in peace it was because they respected certain tribal boundaries and codes of conduct. Furthermore, each tribe had oral histories and myths about themselves and their enemies that they passed on to "create their reality through communication," just as we tell ourselves stories about good guys and bad guys over and over and over again through film, journalism, TV, and now the interwebs. Yes, modern technology certainly made it possible for that to occur on a larger scale, but I can't see what has really changed except the size of groups and the scope and scale of their influence.