The golden rule says nothing about reciprocity. The golden rule is do unto others as you would have them do unto you. It is NOT do unto others as they do unto you.
So if you would have freedom of property rights, then the US should have them whether Mexico does or not.
True, but the full Golden Rule is an ideal, and the right place to start. When I see that it isn't reciprocated at all, I fall back on "Fool me twice." Sorry, that's all I can manage.