The perplexity is not war.  That's easy polemic.  The greater strain on the intellect is where something creeps.  Conquering Poland is simple.  Beating Germany, Italy, and Japan is fairly black and white.  They did what the Big 5 Allies dictated.  But explaining creeping communism, socialism, and capitalism is like explaining the US annexation of Hawaii, the acquisition of the central north american continent by a colony of 13 eastern regions, the 20th century Iran, etc.