So, are you ready to kill your neighbor... or brother... or cousin... or uncle to correct it?
If you can honestly say that enough Americans will organize into combat units and are willing to kill their own countrymen; their own kin, if necessary, to correct this... then there might be a civil war.
If not, there won’t.
In the grand scheme of things, the loss of a few hundred thousand communists to save the republic would be a just tradeoff. Better dead than red.