Cathy Young is a Reason contributing editor and an associate editor at ArcDigital.

The rise of authoritarianism and the fraying of the liberal order is the most pressing issue of our time, and Robert Kagan’s Post essay, “The strongmen strike back,” is a seminal contribution to the subject. Kagan makes a compelling case that we have underestimated liberalism’s vulnerability, especially to attacks from the traditional authoritarian ideologies that have found a revival in today’s nationalist and populist movements across the West. But his examination of these challenges, and their facilitation by liberalism’s inherent conflicts and shortcomings, glosses over a major part of the picture: the anti-liberal tide on the progressive left.

While Kagan acknowledges that liberalism “is under attack at home, from both the left and the right,” and chides progressives for ignoring or condoning left-wing authoritarianism in places such as Venezuela, he focuses almost entirely on the right-wing threat — partly, it seems, as a corrective to what he believes is the Cold War habit of overrating the anti-liberal danger from the left and underrating the danger from the right. Yet the reality is that in the past decade, illiberal progressivism — coming less from the socialist left than from the identity-based “social justice” left — has played a key role in subverting liberal norms in Western democracies and enabling the far-right backlash.

Progressivism’s illiberal turn can take the form of overt hostility to liberal values. Left-wing rhetoric often treats Enlightenment liberalism as hopelessly tainted by its founders’ racist and sexist sins, if not a mere cover for white male privilege and colonialist atrocity; the Enlightenment is even blamed, dubiously, for generating racism itself. While this indictment targets liberalism’s very real failures at universalism, it elides the fact that tribalism, brutal conquest and oppression have been humanity’s common lot throughout history and that liberalism is unique in its effort to reject and overcome these ills.

Perhaps even more insidiously, much of today’s progressive politics turns core liberal values — freedom from oppression, fair and equal treatment for all — against liberalism itself. To some degree, tensions between liberty and equality are inherent to liberalism; but the current version of social justice pushes these conflicts to breaking point.

For one, this ideology is intensely hostile to freedom of speech, as recent clashes over “political correctness” demonstrate. Its adherents believe that any dissent from progressive dogma on issues affecting traditionally oppressed groups — racial or religious minorities, women, gays, etc. — causes harm and must be shut down. (On these grounds, some students at Sarah Lawrence College are currently trying to get a professor’s tenure revoked because he criticized a lack of viewpoint diversity in campus programs.) In Britain, the progressive war on speech has resulted in police investigations of people who have expressed skepticism online about the claims of transgender activists.

Antagonism toward the presumption of innocence for the accused in sex-crimes cases is another instance in which progressive dogma is hostile to basic liberal values. More fundamentally, identity-based progressivism rejects one of the greatest gains of liberalism in the 20th century: the principle that people should be treated as individuals regardless of race, sex, ethnicity, religion or other group characteristics. The critique of racism, sexism and other bigotries has morphed into polemics against white or male privilege that not only vastly oversimplify social dynamics in 21st-century liberal democracies but also easily turn into white- and male-bashing, justified as “punching up.” After the massacre of Muslim worshipers in Christchurch, New Zealand, by an Australian white nationalist, a major progressive publication asserted that the shootings “should implicate all white Australians.”

With its utopian quest for a society cleansed of all traces of bias or inequality and its politicization of everything from art to family life, social-justice leftism is in some ways the modern heir to 20th-century communism. While it does not command totalitarian regimes, its effect on Western liberal institutions — especially the media and academia — makes it a genuine threat to freedom. No less dangerous, however, is its role in the rise of right-wing authoritarianism. Rhetoric assailing “whiteness” and masculinity can lend seeming credence to white-nationalist claims that whites and men are under assault. And vilifying the liberal order as racist, sexist and oppressive is hardly a way to bolster the defense of liberalism against threats from the right.

If the present rise of authoritarian populism merely marks, as a writer in the Nation puts it, “a moment when liberal democracy’s violent and racist tendencies have been unmasked,” why should ordinary citizens believe that the hypocritical mask is worth saving?

Read more: