Since the establishment of the Federal Republic of Germany in 1949, Germans have looked back anxiously to the collapse of the Weimar Republic in the early 1930s and the rise of Nazism. But with many of the world’s democracies under growing strain and authoritarianism on the rise, the lessons of that period should be heeded elsewhere as well.

Start with the fact that economic shocks – for example, inflationary spirals, depressions, and banking crises – are challenges to all governments, everywhere and always. Economic insecurity and hardship persuade people that any regime must be better than the current one. This is an obvious lesson not just from the Weimar years, but also from a large body of research on the economic logic of democracy.

A second key lesson is that under extreme economic conditions, proportional representation (PR) can make matters worse. When a country’s politics are fragmented, PR is more likely to deliver an incoherent electoral majority, usually comprising parties on the far left and the far right that want to reject “the system,” but agree on little else.

Taken together, these two lessons constitute the conventional wisdom among political scientists about the Weimar experience. Too often, though, each lesson is considered in isolation, leading to a dangerous sense of complacency. The first argument lulls people into thinking that only an extreme economic crisis can threaten the political system; the second leads people to assume – incorrectly – that non-PR systems are inherently more robust.

Image: Goldman Sachs

To preempt complacency, it helps to consider eight further lessons from the Weimar era. First, referenda are dangerous, especially when they are rarely used and the electorate has little experience with them. In the Weimar Republic, the National Socialists had virtually disappeared by 1929. But that year, the party was able to reestablish itself by campaigning in a fiercely fought referendum over post-World War I reparations.

Second, dissolving parliaments prematurely when the law does not require it is risky, to say the least. Even a vote that creates the basis for new elections can be interpreted as an admission that democracy has failed. In July 1932, the Nazis won the largest share of the vote (37%) in a free but legally unnecessary election. The previous election had been held less than two years earlier, and another one was not due until 1934.

Third, constitutions don’t necessarily protect the system. The Weimar constitution, designed by some of the day’s most insightful and ethical experts (including Max Weber), was near-perfect. But when unanticipated events – whether foreign-policy dramas or domestic unrest – are interpreted as emergencies requiring an extra-legal framework, constitutional protections can erode rapidly. And the enemies of democracy can foment such events. Similarly, a fourth lesson is that business lobbyists can play a baleful behind-the-scenes role in undermining agreement between parliamentary factions.

Fifth, a political culture in which leaders demonize their opponents erodes democracy. In the Weimar Republic, that pattern began before the Nazis became a significant force. In 1922, Foreign Minister Walther Rathenau was assassinated, after having been subjected to an intense, often anti-Semitic campaign of hatred from the nationalist right. Soon thereafter, Chancellor Joseph Wirth, a center-left Catholic, turned to the right-wing parties in parliament and said, “Democracy – yes, but not the kind of democracy that bangs on the table and says: We are now in power!” He concluded his admonition by declaring that, “The enemy is on the right” – a statement that ended up only fanning the flames of tribalism even more.

Sixth, the president’s family can be dangerous. In Weimar, the aged field marshal Paul von Hindenburg was elected president in 1925, and reelected in 1932. But by the early 1930s, after several small strokes, he was suffering from dementia, and his weak and incapable son, Oskar, controlled all access to him. The result was that he ended up signing whatever agreements were presented to him.

Seventh, an insurgent group does not need to have an overall majority to control politics, even in a PR system. The largest share of the vote that the Nazis ever captured was 37%, in July 1932; in another election held that November, their support had fallen to 33%. Unfortunately, that decline led other parties to underestimate the Nazis, and to regard them as a possible coalition partner.

Eighth, incumbents can survive by buying off a discontented populace for some time, but not forever. In the Weimar era, the German state provided generous municipal housing, local government services, agricultural and industrial subsidies, and a large civil service; but it financed those outlays with debt.

To be sure, the Weimar Republic initially appeared to have a miracle economy. It was only later that German politics soured, as the government sought foreign support. Other countries found it hard to believe the government’s warnings that, without speedy assistance, a political catastrophe would ensue. And it would have been harder still to convince their own electorates to bail out Germany.

It is often assumed that countries with majoritarian electoral systems like those in the United States or the United Kingdom are more resilient than countries with PR systems. After all, America and Britain’s democracies are older, with more deeply entrenched cultures of political civility.

In reality, though, these systems can still become vulnerable over time. For example, the extent to which a country’s economy depends on foreign savings (“other people’s money”) may be politically irrelevant for long periods. But with current-account deficits of 3.7% of GDP in the US and 3% in the UK projected for this year, a reckoning could be in order, especially if isolationist nationalism among American and British voters produces disenchantment among their foreign creditors.