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.
The Founders were not attempting to steal land from a recognized neighboring nation.
This is more akin to Mexicans in Texas, Arizona or California deciding to create an independant nation out of a piece of those States. Would you give it to them? If so, then I suggest you give them your house first!
PS The Founding Fathers didn't deal in sex slaves, drugs, and illegal arms. so don't insult them by comparing them to the Muslim Albanian Mafia stealing Kosovo!
Political self determination only applies to the legitimate owners of the land. Kosovo is majority muslim today only because muslims forcefully invaded it in the 1400's, and have been forcefully driving out its original Serb inhabitants ever since with no compensation for their stolen lands. This invasion has escalated dramatically since 1941 when Kosovar muslims enlisted the assistance of Hitler to drive the remaining Serbs out by force. They left by the hundreds of thousands, and tens of thousands of those who didn't leave were sent to concentration camps or executed on site.