Just out of curiosity should we look to all alliances that America has ever had and then try to somehow equate America's Republic with those it sought an alliance with?
Come on Barrel, be serious. We were allies with the Soviets in WWII after Hitler decided he wanted to eat his cake too.
Communism and Nazism were both forms of socialism, (and communism is also fascistic) albeit with somewhat different characteristics. There were not in any manner, shape,or form different or opposite philosophies. In practices, they are virtually indistinguishable.
American alliances with thugs and dictators over time have one very important difference: they were alliances of convenience against a much greater threat, and had no shared ideological component. The alliance between the Soviets, the Nazis, and Mussolini was both pragmatic and fraternal.
Totalitarian and collectivist systems all, and all with the same fundamental enemy--liberal democracy.