Donald Trump is nothing new. His ilk have been around since the inception of democracy, and since then they have wrought havoc on democratic societies. Our ancient forebears have warned us about them in no uncertain terms. When the demagogue Cleon rose to power in Athens, the cradle of Western democracy, the ancient sources were explicit about the danger he posed, testifying to future generations of the necessity of opposing such figures. And yet, Cleon rises again and again to terrorize democratic societies. Now, he occupies the Oval Office.

After the death of the visionary leader Pericles, Cleon achieved political supremacy through the textbook tactics of demagoguery, flattering the people and promising them small benefits as distractions from the corruption of his regime and the calamity of his policies. “I can fool the [Demos, the people,] any way I please,” says the character of Cleon in Aristophanes’s play “The Knights”. “I know what food he is accustomed to.” In return for the scraps and empty promises they received, the people followed Cleon blindly.

Now Donald Trump offers worthless promises about a border wall, a ban on Muslims, or making America win so much we’ll get tired of winning. In the process, he insults whole nations, ethnicities, and religions; tramples on the civil and human rights of immigrants and refugees; and does nothing to address the real problems facing the country. Yet his promises won him the presidency and still receive support from millions of Americans.

Cleon also used the Peloponnesian War (Athens’s great war with Sparta) to shore up popular support. By riling up the Athenians against an enemy, he could unite them behind himself. Now Trump uses apocalyptic and deeply misleading rhetoric about crime, immigrants, Muslims, and the economy to create a climate of existential fear in which he positions himself as the sole source of salvation.

Why did Cleon want power? For power’s sake, no doubt, but also to enrich himself. The comedies of Aristophanes are replete with accusations that Cleon embezzled money from the state coffers and perpetuated the war to extort money from weaker cities.

In just his first three weeks in power, Donald Trump has created countless financial conflicts of interest; White House Counselor Kellyanne Conway promoted Ivanka Trump’s product line; Eric Trump cost taxpayers nearly $100,000 on a business trip to Uruguay; Trump’s travel ban notably excluded every Middle Eastern country where the Trump Organization does business; Trump hosted Prime Minister Shinzo Abe of Japan at his resort, giving it free international publicity; and questions fester about the extent of his business ties to Russia. The mixing of public power with the accumulation of private wealth was a hallmark of ancient tyrants and demagogues, and the pattern evidently persists today.

Cleon and Trump have also demonstrated the same weakness: a thin-skinned inability to endure ridicule. Aristophanes wrote play after play mercilessly mocking Cleon, driving Cleon into a rage and even prompting him to sue Aristophanes. Trump has shown a furious obsession with Saturday Night Live's portrayal of him and his administration, becoming upset about each new skit. He has also, like Cleon, sued a comedian who mocked him: Bill Maher.

Most striking, however, is Cleon and Trump’s shared disregard for the norms which form the bedrock of the democratic process. Plutarch describes Cleon’s worst sin, saying, “Cleon stripped the bema of its decorum, setting the fashion of yelling when he harangued the people ... He thus imbued the managers of the city's policies with that levity and contempt for propriety which soon after confounded the whole state.”

Trump’s mockery of a disabled reporter, his condescending midnight tweets, his disparagement of critics and the media, his casual incitements to violence at rallies, his lewd remarks about women, his attacks on federal judges, his unending boasting and unparalleled hyperbole, his pathological mendacity, and even his tendency to speak in rambling or incomplete sentences all subvert the basic standards of civil discourse necessary for the healthy functioning of a democratic society. He has stripped the American bema of its decorum, and the nation risks being confounded.

The uncanny resemblance between Cleon and Trump is a shrieking alarm bell. Cleon’s reign was disastrous for Athens. His “Athens First” policies anticipated Trump’s “America First” platform: He prolonged the Peloponnesian War in the hopes of Athenian domination and harshly treated subject cities in Athens’s empire, leading to Athenian defeat. He also replaced bluster with wisdom in the deliberations of the Assembly, enabling additional power-hungry demagogues to rise to prominence and sustain Athens’s decline after his death.

Athens never regained the power it once held. It was surpassed first by Sparta, then Thebes. Athenian democracy returned, but the damage to Athenian power had already been done. Like the rest of the city-states, weakened by almost constant warring, Athens finally lost the independence it had enjoyed since its foundation to the conquering armies of Macedon.

Will the United States go the way of Athens, unable or unwilling to stop a demagogue from undermining its democracy and ruining its international power? Will liberal democracies go the way of the independent Greek city-states, crippled by internal chaos and nationalist tensions? These questions are too big to answer by analogy, but analogy demands that they be asked.

History sings to us of the triumphs and follies of civilization, bearing the combined wisdom of millennia of human experience. At this moment, it screams at us to heed its warnings. Yet there are none so deaf as those who will not hear.