On this day eighty years ago, with no possibility of escape, and death in a Nazi concentration camp a near-certainty, Walter Benjamin took a fatal overdose of morphine.

He stood on the frontiers of Europe on the night of 25 September 1940 facing the inevitability of his death. He had come to Portbou, a Spanish border town in the hills of Catalonia seeking passage to Portugal, and then on to the United States and safety. But the Spanish authorities informed him that he would be returned to German-occupied France the next day. A German Jew, an intellectual, and a Marxist, Benjamin well knew what that would mean.

He had been on the move since 1933 seeking safe haven, finally settling in his beloved Paris. Friends and colleagues who had fled to the United States had urged Benjamin to follow them across the Atlantic, but he would not come. He was utterly committed to European civilization and, right up to the Nazi invasion of France, he could not conceive that Europe would fall to barbarism and genocide. “Besides,” Hannah Arendt noted in Men in Dark Times, “nothing drew him to America, where, as he used to say, people would probably find no other use for him than to cart him up and down the country to exhibit him as the ‘last European.’”

I used to wonder how so many central European Jews, intellectuals, and leftists could have waited so long to escape Nazi and fascist Europe in the 1930s. There were practical, legal, logistical and financial barriers to emigration, but those were hurdles to be overcome, and not impenetrable obstacles. If my reading of central European history and literature shows anything, it is that many of these German, Austrian, and Hungarian Jews, intellectuals, and leftists, though worried and anxious, did not even try to leave Europe until it was almost, and more often absolutely too late.

In hindsight, they appear naïve, foolish, or too trusting. Yet, we excuse them that they could not possibly have conceived at the time of atrocity on the scale of the Holocaust. “I must admit that in 1933 and 1934, none of us in Germany and Austria would have contemplated the possibility of one hundredth part, one thousandth part of what was about to break over us a little later,” Stefan Zweig wrote in his memoir The World of Yesterday. I wish I could believe it.

The truth is that every European who could read a book already knew, in 1933, of King Leopold’s Congo, of the genocide of the Herero and Namaqua people in German South West Africa, of the extermination of the Indigenous people of North America. They would have known about the Armenian Genocide from their newspapers, and Arnold Toynbee, and even Henry Morgenthau’s reports of a “campaign of race extermination.” The horror of the Holocaust was certainly conceivable to literate Europe, only the scale and the deliberateness were different.

But the Germans, the Belgians, the Americans, the Turks and, yes, the British and the French, had committed these atrocities on external and internal “others” in their empires. Belgians did not murder Belgians, Americans did not murder Americans, Turks did not murder Turks; these were the operations of empire upon populations external to the body politic. What those central European Jews, intellectuals, and leftists failed to recognize in 1933, 1935 and 1938 was that Nazism was not merely a theatre of cruelty and violence enacted on a political stage, it was not just another, though perverse, 20th century political innovation. It was the, as Arendt wrote in The Origins of Totalitarianism, the application of the logic and practice of empire at home, to the home population.

Europeans believed that they were “Europeans” and “citizens,” rather than subject others, and that they were thus protected by the “rule of law,” and the scruples of “European civilization.” Terrible things like massacres and genocide happened to the “superfluous populations” of empire, or so they thought, so they did not see the full horror of totalitarianism coming. They did not understand that the theatre of cruelty did not sit within or beside the state and the rule of law, but began to supplant it; they felt confident that the institutions of government and civil rights would remain, even as they were circumvented, ignored, and swept aside by naked power.

“With our rooted ideas of justice, we believed in the existence of a German, a European, an international conscience, and we were convinced that a certain degree of inhumanity is sure to self-destruct in the face of humane standards,” Zweig noted. After all, they had asked themselves, how bad could Adolf Hitler really get “in a state where the law was firmly established, the parliamentary majority was against him, and every citizen was assured of his liberty and equal rights by the solemn wording of the constitution?” Zweig mailed the manuscript of The World of Yesterday to his publisher in Stockholm n 21 February 1942 from exile in Brazil. He took an overdose of barbiturates the following day.

It all happened gradually, “one dose at a time, with a short pause after administering it ,” Zweig wrote. It began with an enabling act, the legal fusion of the offices of chancellor and president, emergency powers that followed the Reichstag fire, and the creation of special extrajudicial People’s Courts to condemn enemies of the body politic. It happened so gradually that each step, whether it was the nationalization of the local police, the growth of the spy apparatus, the racial laws, the suppression of dissent, seemed so small and in itself tolerable. They might not have liked what was happening, but the justifications sometimes made sense, or it was acceptable even if they did not agree with them. Many of Germany’s Jews actually welcomed the 1935 Nuremberg Law because it settled their hitherto ambiguous legal status.

Like the proverbial slowly-boiled frog, those central European Jews, intellectuals, and leftists did not immediately notice the waters roiling around them, cooking them alive, until it was almost, or more often, absolutely too late. Sigmund Freud escaped Vienna in 1938, hearing the sounds of Nazi jackboots just behind him; Joseph Roth drank himself to death in Paris less than a month before German tanks rolled down the Champs Elysees. Benjamin, Zweig, and Ernst Toller took their own lives in the hopelessness of exile. Some, like Arendt, Kurt Weill, and Hanns Eisler managed to escape but most – Viktor Ullman, Liesl Frank, OIto Blumenthal, Else Feldmann, Sabina Spielrein, Peter Hammerschlag, Edith Stein, and so many uncountable others – died in the camps, in the fields of the Aktion Reinhard, in prison cells, and in the ghettos.

For much of my life, I could not understand how these educated, informed, brilliant women and men could not have seen it coming. But today I get it as I read the news, and see what is happening all around me in America. One small step step after another, “one dose at a time.” There was the ban on Muslim immigration, the “alternative facts” and the daily assault on reality itself, the family separations and the internment camps at the border, the suppression of dissent, and the secret police in city streets. Each step enraged, but they followed one on another until they did not really seem exceptional any longer. After all, the election was coming, and our democracy and institutions are guaranteed by “the solemn wording of the constitution.” Yet, here we are, on the frontier of history, looking back at the rubble in its wake, and I have a chilling realization: I now know how one slowly boils a frog.