Something the leadership of no state is willing to face --
but never moreso than in the contemporary United States:
The inherent criminality of aggressive war. 

After taking up the subject of "Crimes in the Conduct of War,"
Chief Prosecutor Robert H. Jackson explained:     

The Geneva Protocol of 1924 for the Pacific Settlement of International Disputes, signed by the representatives of 48 governments, declared that "a war of aggression constitutes . . . an international crime." The Eighth Assembly of the League of Nations in 1927, on unanimous resolution of the representatives of 48 member nations, including Germany, declared that a war of aggression constitutes an international crime. At the Sixth Pan-American Conference of 1928, the 21 American Republics unanimously adopted a resolution stating that "war of aggression constitutes an international crime against the human species."

A failure of these Nazis to heed, or to understand the force and meaning of this evolution in the legal thought of the world, is not a defense or a mitigation. If anything, it aggravates their offense and makes it the more mandatory that the law they have flouted be vindicated by juridical application to their lawless conduct. Indeed, by their own law -- had they heeded any law -- these principles were binding on these defendants. Article 4 of the Weimar constitution provided that: "The generally accepted rules of international law are to be considered as binding integral parts of the law of the German Reich" (2050-PS). Can there be any doubt that the outlawry of aggressive war was one of the "generally accepted rules -of international law" in 1939?

Any resort to war -- to any kind of a war -- is a resort to means that are inherently criminal. War inevitably is a course of killings, assaults, deprivations of liberty, and destruction of property. An honestly defensive war is, of course, legal and saves those lawfully conducting it from criminality. But inherently criminal acts cannot be defended by showing that those who committed them were engaged in a war, when war itself is illegal. The very minimum legal consequence of the treaties making aggressive wars illegal is to strip those who incite or wage them of every defense the law ever gave, and to leave war-makers subject to judgment by the usually accepted principles of the law of crimes.

(Somebody be so kind as to wake me when a member of the U.S. Congress shows the willingness to take up this rather important matter with the relevant authorities.  Thanks.)

Nuremberg Trial Proceedings, Second Day, November 21, 1945, Transcript pp. 145-146