Using an arguably efficient means of eradicating a foreign people, considered by many to be the enemy of Western Civilization, is unsettling. If only to forestall a possible future conflict with that enemy. How short is the path to employing equally efficient means to eliminate a percieved domestic threat? The demonizing of an enemy makes it easier to destroy that enemy. "The Communist or radical Islamic threat must be eliminated". It takes no great polemical gymnastic exercise to apply the "Final Solution" to the domestic dissenter.
As Pogo once stated: "We have met the enemy and he is us!"