Which principles should guide American diplomacy–moral and legal ideals or national interest?
Both – I disagree with the premise of your question, that being that the two are mutually exclusive. I believe acting with moral and legal ideals is in our national interest. Proof: our blind loyalty to the travesty of Israeli treatment of the Palestinians. Hard as it might be, we should stand up the the Israel lobby and force them to either treat the Palestinians morally or go it alone. Good luck with that.