I decided to grow a Toothbrush mustache. Well, that's not what I called it. Until I started this story, I had only one name for the thing in mind: a Hitler mustache. An inch of hair that speaks of bottomless evil. A few nights earlier, I had seen Richard Dawkins, the author of The God Delusion, interviewed by Bill O'Reilly, who, citing Stalin and Hitler, said he thought atheists, because of their lack of restraining faith, were more susceptible to evil. To which Dawkins (in essence) replied: both Stalin and Hitler wore mustaches—do we therefore think the mustache was the cause of their behavior? I experienced this as an epiphany: By Jove! I said to myself. It was the mustache! From that moment, I stopped shaving. From that moment, I started reading. From that moment, I became wrapped up in facial hair, and the role it has played in politics. The Toothbrush mustache offered a new way to look at the past. It was a pinprick through which I could see the old scene from a fresh angle. It was the history of our time retold as the story of the 'stache.

The Toothbrush mustache is the most powerful configuration of facial hair the world has ever known. It overpowers whoever touches it. By merely doodling a Toothbrush mustache on a poster, you make a political statement. Actually wearing a Hitler mustache, as I planned to do—well, that is like yelling racial epithets in a crowded subway. Wasn't Hitler amazing? Whatever he touched turned to ice. His life ended the long and fabled career of the name Adolf, which had included the stories of Adolph Zukor, Adolphe Menjou, Adolph Ochs, and Adolph Coors. Never again will a pregnant mother innocently consider the name for her son, or imagine shouting it across a teeming playground. As for the Toothbrush mustache, it did not only die with the Führer—it was embalmed with him. It was his essence, and so it has been relegated to the black book of history.

This is the part where I am supposed to explain just why I decided to write this story now. I might talk about the re-emergence of facial hair on the world stage, or the rise of the "new anti-Semitism," or Holocaust denial in Iran, but, the fact is, my interest in the Hitler mustache never started and never ends. It is always. If you're a Jew, the Hitler mustache exists in the eternal present. I grew it for the same reason Richard Pryor said the word "nigger." I wanted to defuse it. I wanted to own it. I wanted to reclaim it for America and for the Jews. My name is Rich Cohen, and I wear a Hitler mustache.

The Imperial, the Walrus, the Stromboli, the Handlebar, the Horseshoe, the Mustachio (also called the Nosebeard or the Fantastico), the Pencil, also called (by idiots) the Mouthbrow—the catalogue is illustrious. (The history of the razor is longer than the history of the mustache, but only by a few minutes.) Most mustaches lie waiting for some Clark Gable or Tom Selleck to fix them in the mind. The greatest are identified with a single man, a bad man, usually, who so wrapped his identity with a particular configuration of facial hair that the two became inseparable. Like the Fu Manchu, in which long tresses hang to the chin, where they can be stroked as the madman laughs. It is named for Sax Rohmer's (racist) villain from the golden age of Hollywood, the bad guy from the B movies who became a symbol for the creeping Asian menace. Or think of the long, droopy Pancho Villa. It was worn by the pistol-flashing Mexican bandito as he chased gringos through the border towns along the Rio Grande. These days, you see it only on Halloween, or at reunion shows of Crosby, Stills & Nash.

The Toothbrush mustache was first introduced in Germany by Americans, who turned up with it at the end of the 19th century the way Americans would turn up with ducktails in the 1950s. It was a bit of modern efficiency, an answer to the ornate mustaches of Europe—pop effluvia that fell into the grip of a bad, bad man.[1] Before that, the most popular mustache in Germany and Austria had been the sort worn by the royals. It was called the Kaiser, and it was elaborate. It was perfumed, styled, teased and trained. It turned up at the ends. It was the old, monarchical world that was about to be crushed by the rising tide of assembly-line America. In other words, in the case of Hitler and his 'stache, America faced an extreme case of blowback.

By the beginning of the century, it had been taken up by enough Germans to draw notice in the foreign press. In 1907, The New York Times chronicled a growing distaste for the import under the headline "toothbrush" mustache: german women resent its usurpation of the "kaiserbart."

In the years before the First World War, the Toothbrush was taken up by a German folk hero, which is the moment it became a craze. Before that, it had been an elite fashion shared by the dandies and swells of Berlin and Vienna. After that, it was worn by every yokel who dreamed of greatness. I am imagining young Hitler poring over newspapers in search of any mention of Hans Koeppen, a Prussian lieutenant who had become a pop star in the manner of the solo aviator, the illusionist, or the tightrope walker. Here is how he was described in The New York Times: "Lieut. Koeppen is 31 years old and unmarried. Six feet in height, slim and athletic, with a toothbrush mustache characteristic of his class."

The moment he appeared in the press with the Toothbrush mustache is like the moment Michael Jordan appeared on the basketball court in Bermuda-length shorts, changing the look of the game forever. In early 1908, Koeppen was given leave from the Prussian Army to cover a New York–to–Paris motor race for Zeitung am Mittag, a German newspaper. When I think of the Hitler who must have followed this race, because it was followed by everyone, I think of the Hitler who loved cars and built the autobahn. (As opposed to the Hitler who killed the Gypsies and the Jews.)

After a disagreement with the German drivers, Koeppen took over. By the time he left Vladivostok, he was a star. The Times: "When he dashes across the German frontier from Russia … the tall, trim young infantry officer"—with the Toothbrush mustache—"may count upon a greeting hardly less joyful than if he were returning from victorious battle."

By the end of the war, the Toothbrush mustache was being sported even by the defeated royals. A last image of the Old World is captured in pictures taken in November 1918, when William Hohenzollern Jr., the son of the Kaiser, the heir to an office that had ceased to exist, was sent into exile. He stands on the deck of an imperial steamer. He wears shiny boots, a greatcoat, a military cap, and a Toothbrush mustache. When he turns to look at the people crowding the shore, showing them only his Toothbrush mustache, he is showing them a picture of their future.

I search the photos that survive of Hitler before Hitler was famous for the moment the 'stache appears. Because that is the moment the Devil gets his horns. In early photos, he is barefaced. The first shot that captures Hitler being Hitler was taken in August 1914, at the Odeonsplatz, in Munich. It was photographed from high above the square and shows thousands of people. Hitler, who was nothing and nobody, is no bigger than a cigarette burn, yet he jumps out. Once you see him, you can't stop seeing him. He wears the sort of grand mustache you expect to see on a barkeep. His eyes glow. A speaker has just read the declaration of war. I shudder when I see this photo, and remind myself he is dead and I am alive.

Experts disagree on the exact year Hitler began wearing the Toothbrush. Ron Rosenbaum, perhaps the only historian to give the mustache its proper due, fixes its appearance with confidence. "It was Chaplin's first, before Hitler's," he writes in an essay from The Secret Parts of Fortune. "Chaplin adopted a little black crepe blot beneath the nose for his Mack Sennett silent comedies after 1915, Hitler didn't adopt his until late 1919, and there's no evidence (though some speculation) that Hitler modeled his 'stache on that other actor's."

But some suggest Hitler began wearing it earlier. According to a recently re-discovered essay by Alexander Moritz Frey, who served with Hitler in the First World War, Hitler wore the mustache in the trenches. Because he had been ordered to. The old bushy mustache did not fit under his equipment. In other words, the mustache that defines Hitler was cut in a shape to fit a gas mask. Which is perfect. Because Hitler was the bastard son of the Great War, conceived in the trenches, born in defeat. He inhaled mustard gas and exhaled Zyklon B. In another memoir, dismissed by some as a fraud, Hitler's sister-in-law Bridget claims she was the cause of the mustache. Bridget Hitler was Irish and lived in Liverpool, where, according to the memoir, the young Adolf spent a lost winter. Bridget (or whoever) says she often bickered with her brother-in-law. Because he was disagreeable, but mostly because she could not stand his unruly 'stache. In one of the great inadvertent summaries of historical character, she writes that in this, as in everything, he went too far.

He was wearing the Toothbrush at the first Nazi meetings, when there were just a few people in a room full of empty chairs. One day, an early financial supporter of the Nazi Party advised Hitler to grow out his mustache. He did this delicately but firmly, in the manner of a man trying to protect an investment. The mustache made the Nazi look freakish. Hitler was advised to grow it at least "to the end of the lips." Hitler was a vain man, and you can almost feel him bristle. Here's what Hitler said: "If it is not the fashion now, it will be later because I wear it."

In the coming years, the Toothbrush mustache would belong to just two men, Chaplin and Hitler. The funniest and the scariest. The dialectic of history. For many people, the Toothbrush mustache became no less a symbol of evil than the cloven hoof.

But here's the big question: Did the mustache affect history, or was it just a matter of style? Did it attach itself to a person and drive him crazy? Was the man in charge, or was the mustache calling the shots? Ron Rosenbaum argues that the presence of Chaplin's 'stache on Hitler's face encouraged Western leaders to underestimate the Führer. "Chaplin's mustache became a lens through which to look at Hitler," he writes. "A glass in which Hitler became merely Chaplinesque: a figure to be mocked more than feared, a comic villain whose pretensions would collapse of his own disproportionate weight like the Little Tramp collapsing on his cane. Someone to be ridiculed rather than resisted."

In 1942, Vidkun Quisling, the premier of Norway, whose name, because of his sellout to the Nazis, became synonymous with treachery, forbade Norwegian actors from mustache wearing. Because thespians had been donning the 'stache to parody the Führer. "The purpose of this singular ordinance is … to halt 'actor-pranks' that have been 'stopping the show' by affecting a Hitler mustache," The New York Times reported. Note how, in this story, the Toothbrush mustache is not identified as the Toothbrush mustache but as the Hitler mustache. From then on, the Toothbrush would belong only to Adolf. Not just a symbol but a totem of the dictator. A voodoo doll. It's not hard to see how you go from here to the plan cooked up by officers of the Office of Strategic Services, the precursor to the C.I.A., to inject estrogen into Hitler's food—female hormone that would make Hitler grow weepy, make Hitler grow breasts, and, crucially, destroy his mustache. A smooth-faced Adolf would lose confidence and fall from power. I mean, without the mustache, is Hitler even Hitler?

When Hitler died, he took his mustache with him. Not even the most cutting-edge stylist can pry them apart. If you dress like Chaplin, you run the risk of being mistaken for Hitler, as, if you dress like Evel Knievel, as I do when it rains, you run the risk of being mistaken for Elvis. The Vandyke, the Goatee, the Soul Patch, these things can become the objects of nostalgia, but the Hitler mustache is never coming back.

You could not wear a Toothbrush mustache after World War II, obviously. Because if you did, you were Hitler. In fact, you could not wear any kind of mustache after the war, because, running from Hitler, you might run into Stalin. Hitler plus Stalin ended the career of the mustache in Western political life. Before the war, all kinds of American presidents wore a mustache and/or beard. You had John Quincy Adams, with his muttonchops. You had Abe Lincoln, whose facial hair, like his politics, was the opposite of Hitler's: beard full, lip bare. You had James Garfield, who had the sort of vast rabbinical beard into which whole pages of legislation could vanish. You had Rutherford B. Hayes, Grover Cleveland, and Teddy Roosevelt, whose asthma and elephant gun were just a frame for his mustache. You had William Howard Taft—the man wore a Walrus!

After the war, the few American politicians who still wore a mustache were those who had made their name before Hitler and so had been grandfathered in. Like Thomas Dewey. Dewey was Eliot Spitzer. He was a prosecutor in New York in the 1930s (and later governor), the only guy with the guts to take on the Mob. For Dewey, the rise of Hitler was a fashion disaster. Because Dewey wore a neat little mustache. Dewey ran for president twice—losing to F.D.R., losing to Truman. In my opinion, without the mustache, the headline in the Chicago Daily Tribune (dewey defeats truman) turns true. One of the few prominent American politicians to wear facial hair in recent memory is Al Gore, who grew a Grizzly Adams beard after he lost to George Bush, in 2000. The appearance of this beard was taken to mean either (1) Gore would never again run for office, or (2) Gore had gone completely mental. The decision to grow a mustache or a beard is all by itself reason to keep a man away from the nuclear trigger.

As a player in political life, the mustache lives on only in the Third World—a conclusion drawn not from any statistical analysis but from my own travels. You see the mustache on politicians in such lands the way you see old Peugeots in the French Antilles. It is the past. It is what we left behind. In the Third World, a portion of voters still go for the sort of hair-growing display that once brought the Volk to Hans Koeppen. Until recent events caused me to re-assess, I even entertained a theory—my only stab at a Tom Friedman–like, one-phrase-tells-all formulation—which I call "¿Quien es mas macho?" According to this theory, a country led by a man with a mustache is more likely to start a war, and more likely to lose it.[2] Because such a country is certain to value machismo over the nerdy qualities that actually win wars. A macho leader will counter a tank division with a cavalry charge—or promise, on the eve of battle, to drive his enemies into the sea. Such a leader will make some of the same mistakes as Hitler: he will overvalue physical courage; he will call on supernatural forces; he will consider even the smallest skirmish a "test of wills"; worst of all, he will answer the question "How will we win?" with the question "¿Quien es mas macho?"

I cut my beard on a Friday. I did what everyone who has ever cut a full beard does: I took it through every configuration. Like passing over the stages of man, or watching cultures rise and fall until the face of Hitler emerged. I went to the closet. What would the Führer wear on a sunny day? It does not matter, I decided. Because I am Hitler—whatever I wear, Hitler is wearing. A dozen Hitlers passed through my mind: Hitler in a sport coat; Hitler in a lab coat. Hitler in a Speedo; Hitler in a Camaro. I shook myself and said, "Get it together, Hitler—you're losing your mind!"

I went out. In the street, some people looked at me, but most looked away. A few people said things after I passed. One man gave me a kind of Heil, but it was lackadaisical, and I am fairly certain he was being ironic. (People can be so mean!) Even friends said nothing until I asked, or else acted embarrassed for me. A woman said, "I think you were more handsome without the mustache." I had been worried someone might try to hurt me. I imagined toughs from the Jewish Defense League attacking with throwing stars—Jewish throwing stars! But it turns out, when you shave like Hitler, you follow the same rule you follow with bees: They're more scared of you than you are of them. Because either you really are Hitler, or you're a nut. So people do with little Hitlers what people always do with lunatics in New York, the harmless or dangerous—they ignore, they avert, they move away. If you want to fly coach without being hassled, grow a Toothbrush mustache.

I wore the mustache for about a week. It preceded me into stores and hung in the air after I exited. It sat on my face as I slept. I was Hitler in my dreams. I went to the Jewish Museum. I went to Zabar's. I went to the Met. I went to the modern wing. I said, "All of this art is decadent." I stood on the corner of 82nd and Fifth. I stared into space. When you stare into space with a Toothbrush mustache, you are glowering. You can't help it. You're looking into crowds. You're looking at the names on the census that end in "-berg" and "-stein" while thinking, How do we get all these Juden onto trains? But in the end, my project, in its broader aims, was a failure. Because no matter how long, or how casually, or how sarcastically I wore the mustache, it still belonged to Hitler. You cannot claim it, or own it, or clean it as a drug lord cleans money. Because it's too dirty. Because it's soaked up too much history. It's his, and, as far as I'm concerned, he can keep it. When you wear the Toothbrush mustache, you are wearing the worst story in the world right under your nose.

Rich Cohen is a regular contributor to Rolling Stone and is the author of Sweet and Low: A Family Story and Tough Jews, among other books.