Sort:  

I suppose it would be the American government just to make sure people that will cause trouble, like criminals or terrorists do not get past.

OK, but governments (including the US) routinely declare peaceful people to be "criminals" or even "terrorists." And you are still just assuming they have the authority to claim territory and enforce access. Where does that come from?

It's just my point of view I could be wrong. There's no need for further argument. The control can only be done by a just government, and no government of the world including that of the US is just in this sense. They only do right things when it suits them. Again, I could be completely wrong. Thanks for sharing your point of view on this very sensitive matter.