On February 27, 1933 the German Parliament building burned, Adolf Hitler rejoiced, and the Nazi era began. Hitler, who had just been named head of a government that was legally formed after the democratic elections of the previous November, seized the opportunity to change the system. “There will be no mercy now,” he exulted. “Anyone standing in our way will be cut down.”

The next day, at Hitler’s advice and urging, the German president issued a decree “for the protection of the people and the state.” It deprived all German citizens of basic rights such as freedom of expression and assembly and made them subject to “preventative detention” by the police. A week later, the Nazi party, having claimed that the fire was the beginning of a major terror campaign by the Left, won a decisive victory in parliamentary elections. Nazi paramilitaries and the police then began to arrest political enemies and place them in concentration camps. Shortly thereafter, the new parliament passed an “enabling act” that allowed Hitler to rule by decree.

After 1933, the Nazi regime made use of a supposed threat of terrorism against Germans from an imaginary international Jewish conspiracy. After five years of repressing Jews, in 1938 the German state began to deport them. On October 27 of that year, the German police arrested about 17,000 Jews from Poland and deported them across the Polish border. A young man named Herschel Grynszpan, sent to Paris by his parents, received a desperate postcard from his sister after his family was forced across the Polish border. He bought a gun, went to the German embassy, and shot a German diplomat. He called this an act of revenge for the suffering of his family and his people. Nazi propagandists presented it as evidence of an international Jewish conspiracy preparing a terror campaign against the entire German people. Josef Goebbels used it as the pretext to organize the events we remember as Kristallnacht, a massive national pogrom of Jews that left hundreds dead.

The Reichstag fire shows how quickly a modern republic can be transformed into an authoritarian regime. There is nothing new, to be sure, in the politics of exception. The American Founding Fathers knew that the democracy they were creating was vulnerable to an aspiring tyrant who might seize upon some dramatic event as grounds for the suspension of our rights. As James Madison nicely put it, tyranny arises “on some favorable emergency.” What changed with the Reichstag fire was the use of terrorism as a catalyst for regime change. To this day, we do not know who set the Reichstag fire: the lone anarchist executed by the Nazis or, as new scholarship by Benjamin Hett suggests, the Nazis themselves. What we do know is that it created the occasion for a leader to eliminate all opposition.

In 1989, two centuries after our Constitution was promulgated, the man who is now our president wrote that “civil liberties end when an attack on our safety begins.” For much of the Western world, that was a moment when both security and liberty seemed to be expanding. 1989 was a year of liberation, as communist regimes came to an end in eastern Europe and new democracies were established. Yet that wave of democratization has since fallen under the glimmering shadow of the burning Reichstag. The aspiring tyrants of today have not forgotten the lesson of 1933: that acts of terror—real or fake, provoked or accidental—can provide the occasion to deal a death blow to democracy.

The most consequential example is Russia, so admired by Donald Trump. When Vlaimir V. Putin was appointed prime minister in August 1999, the former KGB officer had an approval rating of 2 percent. Then, a month later, the bombs began to explode in apartment buildings in Moscow and several other Russian cities, killing hundreds of citizens and causing widespread fear. There were numerous indications that this was a campaign organized by the KGB’s heir, now known as the FSB. Some of its officers were caught red-handed (and then released) by their peers. A Russian parliamentarian announced one of the “terror” attacks several days before the bomb actually exploded.

Putin blamed Muslim terrorists and began the war in Chechnya that made him popular. He thereafter exploited more terrorist attacks to consolidate his rule: three years later, Russian security forces ended up gassing to death Russian civilians in a botched response to an attack at a Moscow theater. Putin used the negative press coverage as a justification for seizing control of television. In 2004, after the Beslan massacre, in which terrorists occupied a school and killed a large number of parents and children during a violent confrontation with Russian forces, Putin abolished the position of elected regional governors. And so the current Russian regime was built.

Once an authoritarian regime is established, the threat of terrorism can be used to deepen repression, or indeed to promote it abroad. In 2013 and 2014 the Russian media spread hysterical reports about a non-existent Ukrainian terrorist threat as the Russian army prepared and then fought a war in Ukraine. In 2015, Russia hacked into a French television channel, pretended to be ISIS, and broadcast messages apparently intended to frighten the French population into voting for the National Front, the far-right party financially supported by Russia (and whose leader, Marine Le Pen, is expected to reach the second round of the French presidential elections to be held this April and May). In 2016, the Russian media and Russian diplomats engaged in a large-scale disinformation campaign in Germany, spreading a false tale about refugees raping a girl of Russian origin—again with the likely aim of helping the German far right.

The use of real or imagined terrorist threats to create or consolidate authoritarian regimes has become increasingly frequent worldwide. In Syria, Russia’s client Bashar al-Assad used the presence of ISIS to portray any opposition to his regime as “terrorists.” Our president has admired the methods of rule of both Assad and Putin. In Turkey, President Recep Tayyip Erdoğan has used the July 2016 coup attempt—which he has called “terrorism supported by the West”—to justify the arrest of tens of thousands of judges, teachers, university professors, and to call for a referendum this spring that could give him sweeping new powers over the parliament and the judiciary.

It is aspiring tyrants who say that “civil liberties end when an attack on our safety begins.” Conversely, leaders who wish to preserve the rule of law find other ways to speak about real terrorist threats, and certainly do not invent them or deliberately make them worse.

In this respect, the Bush administration’s reaction to the September 11, 2001 attacks was not as awful as it might have been. To be sure, 9/11 was used to justify the vast expansion of NSA spying and the torture of foreign detainees. It also became the specious pretext for an ill-considered invasion of Iraq that killed hundreds of thousands of people, spread terrorism throughout the Middle East, and ended the American century. But at least the Bush administration did not claim that Muslims as a whole were responsible, nor try to change the basic rules of the political game in the United States. Had it done so, and succeeded, we might already today be living in a post-democratic country.

If we know the history of terror manipulation, we can recognize the danger signs, and be prepared to react. It is already worrying that the president speaks unfavorably of democracy, while admiring foreign manipulators of terror. It is also of concern that the administration speaks of terrorist attacks that never took place, whether in Bowling Green or Sweden, while banning citizens from seven countries that have never been tied to any attack in the United States.

It is alarming that in a series of catastrophic executive policy decisions—the president’s Muslim travel ban, his selection of Steve Bannon as his main political adviser, his short-lived appointment of Michael Flynn as national security adviser, his proposal to move the US embassy in Israel to Jerusalem—there seems to be a single common element: the stigmatization and provocation of Muslims. In rhetoric and action, the Trump administration has aggrandized “radical Islamic terror” thus making what Madison called a “favorable emergency” more likely.

It is the government’s job to promote both freedom and safety. If we face again a terrorist attack—or what seems to be a terrorist attack, or what the government calls a terrorist attack—we must hold the Trump administration responsible for our security. In that moment of fear and grief, when the pulse of politics might suddenly change, we must also be ready to mobilize for our constitutional rights. The Reichstag fire has long been an example for tyrants; it should today be a warning for citizens. It was the burning of the Reichstag that disabused Hannah Arendt of the “opinion that one can simply be a bystander.” Best to learn that now, rather than waiting for the flames.