But it is in your interest to allow people to cross borders. In many ways. Here's one: What if you wanted to move to another country? Don't assume that everyth

But it is in your interest to allow people to cross borders. In many ways. Here's one: What if you wanted to move to another country? Don't assume that everything will always be going super great in your current country. Other countries will be more likely to accept you if your current country accepts citizen of the other country. Free trade!