There is a long history of using mental illness and "anti-social behavior" as a convenient excuse to silence large groups of people, political opponents, and dissidents. Nazi eugenicists, FBI's COINTELPRO, and more. https://en.wikipedia.org/wiki/Political_abuse_of_psychiatry

It's often not until after the fact when a society recognizes the atrocities committed under a false pretense of public well-being.

There is no easy way out of this crisis. "Eradication of a widespread mental illness that causes dangerous political ideas" is a pseudo-scientific way of describing a dictatorship or civil war.