Not a visa, perhaps, but you’d need a sword, a retinue of armed guards (a few hundred would be good), interpreters, incredible amounts of money (only lords could manage that), and every time you passed into another bit of farmland you’d have to check with the local lord that it was okay, for fear of being captured and held as a hostage for money. And let’s not even start thinking about the notion of an infidel Christian trying to travel through Arab Muslim lands in those times.

Sharing traits are perhaps one of those reasons which should reduce the boundary structures.

But the converse is equally true: if the traits are unique enough, they provide a bond for the group that shares that uniqueness, to the exclusion of others, thus motivating the need for boundaries.

In that case, it is better not to assume human beings have shared traits. It is better to assume that human beings have mutual interests, the most important of which are business interests.

Not true. The borders of today are very porous, compared to the religious, national and cultural boundaries of yesteryear.

These boundaries were usually made when people began assuming, as you do, that all humans share some kinds of similar traits.

While Western countries try to unite, the AMerican government wants to break up Iraq into regions for Sunnies, Shiites, and Kurds. People keep on saying that they have been fighting for thousands of years; they need to have their own countries. Western countries have been fighting for thousands of years, but they are trying to stay united. THe U.S. government and Western media ignore the role of the occupation in fueling the violence in Iraq.