"The consent of all nations is the law of nature."
On the Law of Nations is a powerful brief in favor of what the United States Supreme Court in 1900 declared to be "the customs and usages of the civilized world." (In Paquete Habana, the highest court declared international law to be "part of our law" and therefore binding upon the American government and upon American citizens. Article One, Section Eight of the Constitution gives Congress the power to punish "Offenses against the Law of Nations.") By "international law," Moynihan means the evolving customs and written legal obligations defining international relations and preventing those relations from becoming entirely arbitrary. What makes this brief particularly compelling is Moynihan's honesty regarding the obstacles to achieving his goal.
Despite his stated admiration for Woodrow Wilson, for example, Moynihan cites the policies of President Wilson and of his secretary of state, Robert Lansing, in order to underscore the difficulty of applying international law fairly. Though Wilson's appeal to Congress for war against Germany on April 2, 1917, invoked international law, Wilson and Lansing had schemed to bring about American involvement in the conflict. They had filtered public information through government agencies and had drawn the...