I don't recall the Founders breaking any international laws or boundaries...and this is the 21st century. I'd like to think we've progressed a bit in terms of whose land is whose...I think those aforementioned laws were put in place to prevent occurrences like this from happening.
Have we 'progressed' beyond recognizing "these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable rights, that among these are life, liberty and the pursuit of happiness. That to secure these rights, governments are instituted among men, deriving their just powers from the consent of the governed. That whenever any form of government becomes destructive to these ends, it is the right of the people to alter or to abolish it, and to institute new government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their safety and happiness."
Either you believe in political self determination, or you believe 'international law' should dictate who lives under what government. I note the Founders didn't appeal to 'internation law' when deciding the boundaries of the King's power.