The doctrine or principle of leftist tolerance basically works in the following manner: ambivalence is shown toward one's most dangerous enemies for fear of reprisal while dogmatic restraint is exercized upon the liberties of one's more subdued foes and otherwise upon one's own allies.
<I was just chatting with my former graduate student instructor in international monetary economics at Berkeley who now works at the CIA and he likened this effect to the phenomenon of 'being nice to your enemies even though you hate them and being mean to your friends, like on Seinfeld'. Funny, I must say, but also scary.
John Stuart Mill opined that "the only purpose for which power can be rightfully exercised over any member of a civilized community, against his will, is to prevent harm to others." But who determines whether an act is harmful or harmless? Acts deemed harmless by an individual are not harmless if they subvert the societal bonds of trust and self-restraint upon which liberty itself depends. Which is not to say that all social regimes are regimes of liberty. Liberty requires voice and, above all, exit -- the freedom to choose one's neighbors and associates -- under the general protection of the state, as intended by the Framers of our Constitution. Liberty, because it is a social phenomenon and not an innate condition of humanity, must be won and preserved through politics, policing, and war.