Again... communism did horrible things, yes. Fighting fire with fire as you say, and tolerating and funding and supporting genocide and mass murder against genocide and mass murder is justifiable (but have those crimes been committed against the USA?) would make the second country go down to the same level as the first, assuming it was in a higher level on the first place.
The thing is, in many cases the war against communism was an excuse to make US citizens feel better, while the real motivations were economical or political, and the US intervened against countries who had done nothing against the USA besides, in an example, daring to ask US multinationals to *gasp* pay taxes and give fair wages to their workers. During the XX century, the USA government was very proactive at backing US multinationals with their military, and countries had to either comply or risk getting intervened.
And to talk a bit about communism, as there were some cases where the US intervened because a country had democratically elected a president with communist tendencies, did they have the right to do that, and put in power US friendly brutal dictatorships instead?
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To build may have to be the slow and laborious task of years. To destroy can be the thoughtless act of a single day. - Winston Churchill