Liberty, however, requires certain things. Liberalism demands acceptance of our human differences and the ability to mediate them through democratic institutions. It demands acceptance of multiple, perhaps incompatible truths. In an age of declamation and shouting, of polarization and vilification, of politics-for-sale and the insidious submersion of politics in fact-lite entertainment, the emergence of Trump is as unsurprising as it is menacing.

No wonder Putin admires him. Russian authoritarianism is all about the muscular trappings of power and popular adulation cultivated through fawning media for a Czar-like figure. Berlin noted there was “some truth” to the conservative writer Joseph de Maistre’s view that “the desire to immolate oneself, to suffer, to prostrate oneself before authority, indeed before superior power, no matter whence it comes, and the desire to dominate, to exert authority, to pursue power for its own sake” are forces that are “historically at least as strong as desire for peace, prosperity, liberty, justice, happiness, equality.”

And so history does not end. It eddies back and forth.

The broad failure of the Arab Awakening — the greatest liberation movement since 1989, an attempt by Arab peoples to empower themselves — had many causes, but a central one was the absence of any liberal constituency in societies from Egypt to Libya. Even a country with a large middle class like Egypt was not ready to accept the mediation of multiple truths through democratic institutions. So power went back to the generals, and the Islamists — even the moderates among them — were condemned to prison or worse.

In Russia, and now in countries from Hungary to Poland, and in China, forms of authoritarianism are ascendant and liberalism (or even modest liberalization) are in retreat. In the Middle East, the Islamic State casts its long, digitized shadow. In Western societies beset by growing inequality (neo-liberal economics has also sapped the credentials of liberalism), political discourse, debate on college campuses and ranting on social media all reflect a new impatience with multiple truths, a new intolerance and unwillingness to make the compromises that permit liberal democracy to work.

The threat for liberal Western societies is within and without. Liberalism may be feeble as a battle cry, but nothing is more important for human dignity and decency.