Tragedy has almost as many definitions and meanings as it has actual examples.In terms of foreign policy, tragedy can mean a collision of two seemingly valid principles that come into conflict. In Vietnam, the noble aim of bringing some measure of peace, stability and justice to a war-ravaged country was unachievable under the guise of preventing the spread of "Godless, monolithic communism."Tragedy is also inevitable when the obvious best outcome has no chance of surviving the brutal realities and harsh conditions required to end a conflict or war. Ukraine is the clearest example, as this tragedy continues to devastate that...