Donald Trump and Vladimir Putin share a deeply dangerous trait: They are both Big Liars, and they embrace their own Big Lies.

For Trump, the Furious Falsehood is that he actually won the 2020 election. For Putin, it’s that Ukraine is not a real country and longs to join Mother Russia.

Both beliefs are totally wrong. And for both leaders, their biggest foe turns out to be reality. As the futurist Jaron Lanier told Maureen Dowd of The New York Times, “One of the great truths of history is that the great deceivers also deceive themselves.”

Trump and Putin are united in another way, as well: mutual admiration. Trump never tires of repeating, as he did at a rally in 2016, that Putin once called him a “genius” who “is going to be … the leader of the world or something.”

And Trump could not contain his enthusiasm for the way Putin invaded Ukraine, telling attendees at a fundraiser at Mar-a-Lago: “They say, ‘Trump said Putin’s smart.’ I mean, he’s taking over a country for two dollars’ worth of sanctions. I’d say that’s pretty smart. He’s taking over a country — really a vast, vast location, a great piece of land with a lot of people, and just walking right in.”

Trump later tried to excise his exaltations, but they accurately reflect his longstanding enthusiasm for Putin’s governing style. During one 2016 campaign appearance, Trump passionately praised the Russian dictator: “The man has very strong control over his country. He’s been a leader far more than our president has been a leader.”

Stephanie Grisham, Trump’s former press secretary, says that this lust for Putin’s “strong control” continued throughout his presidency. “I … think he admired him, greatly, I think he wanted to be able to kill whoever spoke out against him,” she said on ABC’s “The View.” “In my experience with him, he loved the dictators.”

Fiona Hill, a Russian expert in Trump’s White House, says the Jan. 6 insurrection was the culmination of his envy and emulation. “I saw the thread,” she said in The New York Times Magazine. “I remembered how, in 2020, Putin had changed Russia’s constitution to allow him to stay in power longer. This was Trump pulling a Putin.”

Putin’s attitudes toward Trump are murkier, partly because he doesn’t trumpet them on Twitter. But he clearly wanted Trump to be president, and tried to help him. A January 2017 report by the Director of National Intelligence concluded: “We assess that Russian President Vladimir Putin ordered an influence campaign in 2016 aimed at the U.S. Presidential Election … We further assess that Putin and the Russian government developed a clear preference for President-elect Trump.”

Trump’s cheerleaders see traces of their hero’s influence on Putin. After the Russian’s attack on Ukraine sputtered badly, he staged a huge rally in a Moscow soccer stadium to create an impression of public support. Sean Hannity, a Trump confidant and Fox News talk show host, proclaimed, “It looks like Vladimir Putin is channeling his inner Donald Trump!” All that was missing were the red MAGA hats.

Satirist Andy Borowitz in The New Yorker effectively skewered both of them, imagining Trump’s advice to his pal in Moscow: “He needs to get on TV and say that he’s the winner. He should say that he had a victory in Ukraine like you wouldn’t believe.”

Clever. And true. Trump and Putin are united by yet another impulse: to control every bit of information the public knows about them and excommunicate all dissenters. During the initial COVID-19 outbreak, Trump repeatedly undermined his own medical advisers when they tried to warn of the pandemic’s severity. And he seems determined to purge a raft of Republicans — from Gov. Brian Kemp of Georgia to Rep. Liz Cheney of Wyoming — who dare to tell the truth: Trump lost in 2020. As a result, 7 of 10 Republicans still say Trump really won.

Putin is following a similar strategy: poisoning and imprisoning his chief critic, Alexei Navalny, and threatening jail for any journalist who contradicts the Kremlin’s official line on Ukraine. As CNN’s Nic Robertson reported: “It’s no surprise that so many people are just following along with the Kremlin’s lies … It’s information they’ve been fed year upon year upon year by Putin and by the Soviet leadership.”

History teaches that the Big Liars always lose — eventually. The insurrectionists storming the U.S. Capitol and the Russian troops besieging the Ukrainian capital both failed. But they have left a lot of wreckage behind.

 Steven Roberts teaches politics and journalism at George Washington University. His new book is “Cokie: A Life Well Lived.” He can be contacted by email at stevecokie@gmail.com.