I fear you yet underestimate the savagery of those that would be kings. WWII saw Russia as not only the ally of the USG, but that most responsible for victory over our former allies, Germany and the rest of the Axis.
It is treachery that provides the greatest advantage in war, and one can only betray trust.
In WWI it was Americans that plotted and schemed to bring about the war in Europe, to strengthen the English empire and cement it's hold on the resources of the world. Cecil Rhodes vision was in many ways brought to life today through those machinations. Wilson's mentor, 'Colonel' House, was integral to this plot, and various allies of both England and the USA were deliberately subjected to slaughter in the trenches.
tl;dr It is by stabbing allies in the back that the most profitable wars are begun.