There are long decades in which history seems to slow to a crawl. Elections are won and lost, laws adopted and repealed, new stars born and legends carried to their graves. But for all the ordinary business of time passing, the lodestars of culture, society and politics remain the same.

Then there are those short years in which everything changes all at once. Political newcomers storm the stage. Voters clamour for policies that were unthinkable until yesterday. Social tensions that had long simmered under the surface erupt into terrifying explosions. A system of government that had seemed immutable looks as though it might come apart.

This is the kind of moment in which we now find ourselves.

Until recently, liberal democracy reigned triumphant. For all its shortcomings, most citizens seemed deeply committed to their form of government. The economy was growing. Radical parties were insignificant. Political scientists thought that democracy in places like France or the United States had long ago been set in stone, and would change little in the years to come. Politically speaking, it seemed, the future would not be much different from the past.

Then the future came – and turned out to be very different indeed. Citizens have long been disillusioned with politics; now, they have grown restless, angry, even disdainful. Party systems have long seemed frozen; now, authoritarian populists are on the rise around the world, from America to Europe, and from Asia to Australia. Voters have long disliked particular parties, politicians or governments; now, many of them have become fed up with liberal democracy itself.

Donald Trump’s election to the White House has been the most striking manifestation of democracy’s crisis. It is difficult to overstate the significance of his rise. But it is hardly an isolated incident. In Russia and Turkey, elected strongmen have succeeded in turning fledgling democracies into electoral dictatorships. In Poland and Hungary, populist leaders are using that same playbook to destroy the free media, to undermine independent institutions and to muzzle the opposition.

More countries may soon follow. In Austria, a far-right candidate nearly won the country’s presidency. In France, a rapidly changing political landscape is providing new openings for both the far left and the far right. In Spain and Greece, established party systems are disintegrating with breathtaking speed. Even in the supposedly stable and tolerant democracies of Sweden, Germany and the Netherlands, extremists are celebrating unprecedented successes.

There can no longer be any doubt that we are going through a populist moment. The question is whether this populist moment will turn into a populist age – and cast the very survival of liberal democracy in doubt.

When democracy is stable, it is in good part because all major political actors are willing to adhere to the basic rules of the democratic game most of the time.

Some of these rules are formal. A president or prime minister allows the judiciary to investigate wrongdoing by members of his government instead of firing the prosecutor. He puts up with critical coverage in the press instead of shutting down newspapers or persecuting journalists. When he loses an election, he leaves office peacefully instead of clinging to power.

But many of these rules are informal, making it less clearcut when they are violated. The government does not rewrite electoral rules months before an election to maximise its chance of winning. Political insurgents do not glorify authoritarian rulers of the past, threaten to lock up their opponents or set out to violate the rights of ethnic and religious minorities. The losers of an election refrain from limiting the scope of an office to which an adversary has been elected in their last days in the job. The opposition confirms a competent judge whose ideology it dislikes rather than leaving a seat on the highest court in the land vacant, and strikes an imperfect compromise about the budget rather than letting the government shut down.

In short, politicians with a real stake in the system may think of politics as a contact sport in which all participants are hustling to gain an advantage over their adversaries. But they are also keenly aware that there need to be some limits on the pursuit of their partisan interests; that winning an important election or passing an urgent law is less important than preserving the system; and that democratic politics must never degenerate into all-out war. “For democracies to work,” Michael Ignatieff, the political theorist and former leader of the Liberal party of Canada, wrote a few years ago, “politicians need to respect the difference between an enemy and an adversary. An adversary is someone you want to defeat. An enemy is someone you have to destroy.”

In the US, and many other countries around the world, that is no longer how democratic politics works. As Ignatieff put the point, we are increasingly “seeing what happens when a politics of enemies supplants a politics of adversaries”. And the new crop of populists who have stormed the political stage over the past decades shoulder a lot of the blame for this.

The rise of political newcomers is as likely to be a sign of democratic health and vitality as it is of impending sickness. Political systems benefit from a thorough competition of ideas and from a regular substitution of one ruling elite for another. New parties can help in both ways. By forcing long-neglected issues on to the political agenda, they increase the representativeness of the political system. And by catapulting a new crop of politicians into office, they inject the system with fresh blood.

Facebook Twitter Pinterest Late far-right politician Jörg Haider speaking in 2000. Photograph: Gert Eggenberger/EPA

Even so, there is good reason to think that the recent thawing of the party system is far from benign. For many of the new parties do not just provide ideological alternatives within the democratic system – they challenge key rules and norms of the system itself.

One of the earliest populists to rise to prominence was Austria’s Jörg Haider, a slick, charismatic politician from Carinthia. But the degree to which he was willing to undermine core norms of liberal democracy became apparent whenever he engaged in a sly revaluation of Austria’s Nazi past. Speaking to an audience including many former SS officers, Haider claimed that “our soldiers were not criminals; at most, they were victims”.

Breaking political norms is also a speciality of Geert Wilders, the leader of the Dutch Freedom party (PVV). Islam, he has argued, is “a dangerous totalitarian ideology”. While other populists have sought to outlaw minarets or burkinis, Wilders, determined not to be outdone, has gone so far as to demand a ban on the Qur’an.

By comparison to Haider and Wilders, a figure like Beppe Grillo seems far more benign at first blush, promising to take power from a self-serving and geriatric “political caste”, and to fight for a more modern and tolerant Italy. But once the Five Star Movement gained in popularity, it quickly took on an antisystem hue. Its attacks on the corruption of individual politicians slowly morphed into a radical rejection of key aspects of the political system, including parliament itself. Anger against the political establishment was sustained by a growing willingness to engage in conspiracy theories or to tell outright lies about political opponents.

The reason why populists and political newcomers are so willing to challenge basic democratic norms is in part tactical: whenever populists break such norms, they attract the univocal condemnation of the political establishment. And this of course proves that, as advertised, the populists really do represent a clean break from the status quo. There is thus something performative about populists’ tendency to break democratic norms: while their most provocative statements are often considered gaffes by political observers, their very willingness to commit such gaffes is a big part of their appeal.

Facebook Twitter Pinterest Beppe Grillo’s Five Star Movement rejects parliament itself. Photograph: Reuters Photographer/Reuters

But their recklessness is no less dangerous for all of that. Once some members of the political system are willing to break the rules, others have a big incentive to follow suit. And that, increasingly, is what they do. While some of the most spectacular attacks on basic democratic norms have come from political newcomers, the representatives of old, established parties have also become increasingly willing to undermine the basic rules of the game.

At times, established parties on the left have given in to the temptation of violating democratic norms. In the US, Democrats have long engaged in unacceptable forms of gerrymandering. And during the Obama presidency, the executive continued to expand its role in some worrying ways, prosecuting a record number of journalists for handling classified information and using executive orders to bypass Congress in policy areas from the environment to immigration. Even so, most political scientists agree that the Republicans are now, by far, the best example for a concerted attack on democratic norms perpetrated by a nominally establishment party. Just take what happened in the wake of the 2016 gubernatorial elections in North Carolina. Roy Cooper, the Democratic candidate, won a highly contentious election by an extremely narrow margin. But instead of recognising that this gave him a mandate to rule for the next four years, Republicans decided to rewrite his job description. North Carolina’s governor used to be responsible for appointing 1,500 gubernatorial staffers; according to a law passed by the outgoing Republican legislature, he would henceforth be permitted to appoint only 425. The governor had previously been charged with appointing up to 66 trustees to the school boards of the University of North Carolina; now, he would be permitted to appoint a grand total of zero.

Facebook Twitter Pinterest Roy Cooper’s victory in elections for governor of North Carolina was undermined by his Republican rivals. Photograph: Jonathan Drake/Reuters

The naked partisanship of these actions is undeniable. So is their import: Republicans in North Carolina have effectively rejected the notion that we resolve political differences by free and fair elections and are willing to submit to the rule of our political rivals when we lose.

Citizens are less committed to democracy than they once were; while more than two-thirds of older Americans say that it is essential to them to live in a democracy, for example, less than a third of younger Americans do. They are also more open to authoritarian alternatives; two decades ago, for example, 25% of Britons said that they liked the idea of “a strongman ruler who does not have to bother with parliament and elections”; today, 50% of them do. And these attitudes are increasingly reflected in our politics: from Great Britain to the US, and from Germany to Hungary, respect for democratic rules and norms has precipitously declined. No longer the only game in town, democracy is now deconsolidating.

That conclusion, I know, is hard to swallow. We like to think of the world as getting better over time, and of liberal democracy as deepening its roots with every passing year. That is perhaps why, of all my claims, the one that has elicited the most scepticism is the idea that young people have been especially critical of democracy.

For good reason, Americans and the British find it especially hard to believe that young people are most disaffected. After all, young people heavily leaned toward Hillary Clinton, the candidate of continuity, in the last US elections: among voters below the age of 30, 55% supported Clinton while only 37% supported Trump. The story of Brexit was very similar. Whereas two-thirds of pension-age Brits voted to leave the European Union, two-thirds of millennials voted for the status quo.

But the attraction of the young to political extremes has grown over time. In countries like Germany, the UK and the US, for example, the number of young people who locate themselves on the radical left or the radical right has roughly doubled over the course of the past two decades; in Sweden, it has increased by more than threefold. Polling data for populist parties bears out this story as well. While young people were less likely to vote for Trump or Brexit, they are much more likely to vote for antisystem parties in many countries around the world.

Marine Le Pen, for example, can count young people as some of her most fervent supporters. In this, France is hardly an exception. On the contrary, polls have found similar results in countries as varied as Austria, Greece, Finland, and Hungary.

Facebook Twitter Pinterest Britain First supporters march in Rochester, Kent. Photograph: Alamy

One possible explanation for why a lot of young people have grown disenchanted with democracy is that they have little conception of what it would mean to live in a different political system. People born in the 1930s and 40s experienced the threat of fascism as children or were raised by people who actively fought it. They spent their formative years during the cold war, when fears of Soviet expansionism drove the reality of communism home to them in a very real way. When they are asked whether it is important to them to live in a democracy, they have some sense of what the alternative might mean.

Millennials in countries such as the UK or the US, by contrast, barely experienced the cold war and may not even know anybody who fought fascism. To them, the question of whether it is important to live in a democracy is far more abstract. Doesn’t this imply that, if they were actually faced with a threat to their system, they would be sure to rally to its defence?

I’m not so sure. The very fact that young people have so little idea of what it would mean to live in a system other than their own may make them willing to engage in political experimentation. Used to seeing and criticising the (very real) injustices and hypocrisies of the system in which they grew up, many of them have mistakenly started to take its positive aspects for granted.

Ever since philosophers began to think about the concept of self-rule, they have put particular emphasis on civic education. From Plato to Cicero, and from Machiavelli to Rousseau, all of them were obsessed with the question of how to instil political virtue in the youth.

It is hardly surprising, then, that the small band of patriots who dared establish a new republic in America at a time when self-government had all but vanished from the earth also thought very hard about how to convey their values to the generations that would come after them. What, George Washington asked in his Eighth Annual Address, could be more important than to pass civic values down to “the future guardians of the liberties of the country”?

Facebook Twitter Pinterest George Washington wrote about the importance of passing down civic values. Photograph: Getty Images

“A people who mean to be their own Governors,” James Madison echoed a few years later, “must arm themselves with the power which knowledge gives.” His fears about what would happen to America if it neglected this crucial task sound oddly apposite today: “A popular Government, without popular information, or the means of acquiring it, is but a Prologue to a Farce or a Tragedy; or, perhaps both.”

For the first centuries of the republic’s existence, this emphasis on civic education shaped the country. Parents sought to raise tomorrow’s citizens, competing with each other to see whose four-year-old could name more presidents. Schools across the US devoted ample time to teaching students “How a Bill Becomes a Law”.

Civic education in all its forms stood at the core of the American project – as it also did in, say, Britain, Germany and Scandinavia. Then, amid an era of unprecedented peace and prosperity, the idea that support for self-government had to be won anew with every passing generation started to fade. Today, it is all but extinct.

Many conservative thinkers have suggested a simple remedy to these complex ills. As David Brooks put the point in a recent New York Times column, the history of western civilisation should be taught in a “confidently progressive” manner: “There were certain great figures, like Socrates, Erasmus, Montesquieu and Rousseau, who helped fitfully propel the nations to higher reaches of the humanistic ideal.” Brooks is right to emphasise the importance of civic education. But he is wrong to suggest that the future of civics should consist in quite so hagiographic an account of the past. For all of its flaws, there is, after all, an important kernel of truth to the critiques that parts of the academic left level against liberal democracy. Even though they aspired to universality, many Enlightenment thinkers wound up excluding large groups from moral consideration. Even though they have huge accomplishments to their name, many of the “great men” of history committed horrifying misdeeds. And even though the ideal of liberal democracy is very much worth defending, its current practice continues to tolerate some shameful injustices.

Facebook Twitter Pinterest Protests in Iceland against the government’s mishandling of the financial crisis in 2010. Photograph: NordicPhotos/Getty Images

Both the history of the Enlightenment and the reality of liberal democracy are complex. Any attempt to present them in uncritical terms is bound to run counter to the basic Enlightenment value of veracity, and to undermine the basic democratic principle of striving toward political equality. It is the recognition of these facts – as well as understandable anger at the blithe dismissal of them on large parts of the right – that makes it so tempting for many of today’s journalists and academics to settle into a pose of pure and persistent critique.

But an exclusive focus on today’s injustices is no more intellectually honest than an unthinking exhortation of the greatness of western civilisation. To be true to its own ideals, civic education thus needs to feature both the real injustices and the great achievements of liberal democracy – and strive to make students as determined to rectify the former as they are to defend the latter.

One integral part of this education should be an account of the reasons why the principles of liberal democracy retain a special appeal. Teachers and professors should spend much more time pointing out that ideological alternatives to liberal democracy, from fascism to communism, and from autocracy to theocracy, remain as repellent today as they have been in the past. And they should also be much more clear about the fact that the right response to hypocrisy is not to dismiss appealing principles that are often invoked insincerely but rather to work even harder for them to be put into practice at long last.

As I argue in my new book, The People vs. Democracy, we will only be able to contain the rise of populism if we ensure that the political system overcomes the very real shortcomings that have fuelled it. Ordinary people have long felt that politicians don’t listen to them when they make their decisions. They are sceptical for a reason: the rich and powerful really have had a worrying degree of influence over public policy for a very long time. The revolving door between lobbyists and legislators, the outsized role of private money in campaign finance, and the tight links between politics and industry really have undermined the degree to which the popular will steers public policy.

All of this has had a large impact on the government’s ability to deliver for ordinary people. After growing rapidly in the postwar era, the living standards of ordinary people have, in many North American and western European countries, been stagnating for decades. And the growing frustration about a lack of material progress has, in turn, helped to fuel a massive cultural backlash against the ideals of an equal, multi-ethnic society.

These shortcomings can only be addressed through substantial reform. Institutions need to curb the influence of money on politics and find new ways to allow citizens to have a say. Politicians need to recover the will and the imagination to ensure that the fruits of globalisation and free trade are distributed much more equally. And citizens – which is to say all of us – need to work even harder to build an inclusive patriotism that protects vulnerable minorities against discrimination while emphasising what unites rather than what divides us.

But the project of saving liberal democracy also calls for something more high-minded than wonkish reform. Populists have only been able to celebrate such astounding successes because the moral foundations of our system are far more brittle than we realised. And so anybody who seeks to make a contribution to revitalising democracy must first help to rebuild it on a more stable ideological footing.

• Yascha Mounk is a lecturer on government at Harvard and the author of the new book The People vs. Democracy: Why Our Freedom is in Danger and How to Save It