You are certainly entitled to your opinion, but oddly, I do not find such language contained in the Constitution, that war is only legal and moral when it fits such a definition - only that Congress may declare war, without specifying what the grounds for a declaration must or should be. One may appeal to extra-Constitutional texts in support of such a thesis, but the Constitution itself makes no such distinction between moral and immoral wars.
Washington and Jefferson both made it very clear, what sort of foreign policy they envisioned. It is clearly one driven by both a respect for the Law of Nations and the dictates of morality in a Republican system. (See An American Foreign Policy.)
We have had now almost 85 years--since Wilson brought the League Treaty home in November, 1918--of arguments for a different foreign policy; but they never confront the far more compelling arguments that the Founding Fathers made for the one they gave us. (Rather the technique has been to blow smoke in the public face, with allegations that our traditions were "isolationist." But nothing could be further from the truth.)
William Flax Return Of The Gods Web Site