What is the single most important issue before us?

To ask the question is either to invite scoffing (how can any one issue be described in this way?) or to call forth a cacophony of replies. For starters: the North Korean confrontation, globalization, climate change, rising inequality, terrorism or the ongoing troubles in the Middle East.

But at the risk of being accused of cultural imperialism, I’d argue that the challenge to liberal democracy is far and away the most consequential question facing the world. If liberal democracy does not survive and thrive, every other problem we face becomes much more difficult.

The very phrase “liberal democracy” is vexed. In the United States, “liberal” is associated with a New Dealish center-left. Elsewhere, particularly in Europe, it often implies minimal governmental interference with the workings of capitalism.

But liberal democracy is, in principle, a simple if also profound idea: a belief in governments created through free elections and universal suffrage; an independent judiciary; and guarantees of the freedoms of speech, assembly, religion and press. Some of my more libertarian-leaning friends — and in our shared desire to defend liberal democracy, we are friends — would define it as excluding various forms of regulation and redistribution.

Vice President Pence told reporters that he is confident of reaching a "peaceable" solution for Venezuela on Aug. 15 in Buenos Aires. (Reuters)

I’d agree with them that the right to private property is a characteristic of liberal societies but insist that there is also an important place for social insurance, government provision of various services (education and health care among them) and rules protecting workers, consumers and the environment. Indeed, the vast inequalities that capitalism can produce when unchecked typically undermine liberal democracy and are doing so now.

For those who claim that liberal democracy is simply a Western idea, consider that India is the world’s largest democracy and that many nations in Africa, Latin America and other parts of Asia are working democracies or struggling for democratic rights.

Liberal democracy is essential for solving every other problem because it assumes that history is open and that free electorates can change their minds and their governments. Oppressed groups have a right to agitate and organize against injustices, and new ways of reforming society are given room to emerge.

But is there a crisis of liberal democracy? We could argue for days over whether the word “crisis” is appropriate, which is why I like the more modest title of Financial Times columnist Edward Luce’s compelling book published this year, “The Retreat of Western Liberalism.” Crisis or not, liberal democracy is in trouble — partly because, in the years after World War II, liberal democrats became complacent.

Luce affectingly describes the elation he felt when he and a group of fellow students raced to Berlin as the Wall was coming down: “Borders were opening up. Global horizons beckoned. . . . Though still alive, history was smiling.”

But history is starting to scowl as once-solid democracies (Hungary, Poland and Turkey, along with many outside Europe) move in an autocratic direction. China, meanwhile, offers a path to development and growth that involves neither freedom nor democracy.

Even where liberal democracy has its strongest foundations, authoritarian brands of populism have gained ground by exploiting widespread discontent. Luce is especially powerful when taking to task those at the global economy’s commanding heights for failing to address the stagnation of middle- and working-class incomes. “The world’s elites have helped to provoke what they feared: a populist uprising against the world economy.”

Twenty-year-old protest leader Joshua Wong and two other young activists received prison sentences for their part in the 2014 Umbrella Movement protests in Hong Kong. (Reuters)

In 2017, there has been something of a liberal democratic comeback — in France, the Netherlands and, it would appear from the polls, Germany. Movements of the far right are (at least for now) receding. My Post colleague Fred Hiatt recently pointed to “the Trump boomerang effect” as other nations learn from the mistake the United States made in November.

And we should not petrify ourselves with too many comparisons between our time and the 1930s. On the eve of World War II, as historian Ian Kershaw reminds us in “To Hell and Back,” his monumental history of Europe from 1914 to 1949, three-fifths of Europeans lived under authoritarian regimes — a calculation that does not even include Joseph Stalin’s Soviet Union.

We are far from such a catastrophe, but I’m grateful to Luce and others for warning us not to take liberal democracy for granted. When liberal democrats become arrogant and forget that governments have an obligation to create the circumstances for widespread well-being, autocrats will always be there offering security and prosperity in exchange for less freedom. Liberal democracy must be defended. It must also deliver the goods.

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