Oh, the cruel irony. President Trump is planning to turn the Fourth of July celebrations into his own “Salute to America.” And yet, while attending the Group of 20 summit in Osaka, Japan, Trump made clear that he has no idea what America is all about.

Just before coming to Osaka, Vladimir Putin attacked liberal democracy in an interview with the Financial Times. The Russian despot claimed that “the liberal idea” — which he maliciously defined as allowing “migrants” to “kill, plunder and rape with impunity” — had become “obsolete.” Any normal democratic leader should have reacted as Donald Tusk, president of the European Council, did. He said, “What I find really obsolete is authoritarianism, personality cults, and the rule of oligarchs.”

But when Trump was asked by Peter Baker of the New York Times about Putin’s attack on “Western-style liberalism,” he responded by criticizing San Francisco and Los Angeles, which he said are “sad to look at” because they are “run by liberal people.” So Trump doesn’t know the difference between West Coast liberalism and Western liberalism — between supporting the Green New Deal and supporting the immortal words of the Declaration of Independence that all people are endowed “with certain unalienable Rights,” including “Life, Liberty, and the pursuit of Happiness.” It is the issuance of the Declaration of Independence that we celebrate on July 4. But Trump is clueless. For him it’s just another chance to stage a garish spectacle with himself at the center.

The Founding Fathers would be gathering again in Philadelphia if they could hear George Washington’s successor praise Putin — who makes King George III look like a choirboy — as a "great guy” and a “terrific person.” Asked by a reporter if he would confront Putin over his attack on the 2016 election, Trump treated it as a big joke, saying sarcastically, “Don’t meddle in the election, president” while wagging his index finger and laughing. He later said that Putin “denies it totally,” thus reprising his surrender in Helsinki.

Trump and Putin bonded over their shared antipathy to “fake news” — meaning accurate if embarrassing reporting. “You don’t have this problem in Russia,” Trump complained, “but we have it.” Of course they don’t have “this problem” in Russia, because they have no freedom of the press. Trump seems jealous that Putin can censor the press and kill journalists. The First Amendment — what a nuisance!

And speaking of killing journalists: Trump acted buddy-buddy with Saudi Crown Prince Mohammed bin Salman, who has been implicated by both the U.S. intelligence community and the United Nations in the death and dismemberment of Post contributor Jamal Khashoggi. “I want to congratulate you. You’ve done a really spectacular job,” Trump told “his friend,” the Saudi despot. Trump’s embrace of MBS renders hollow his supposed outrage over Khashoggi’s murder.

Trump was just as effusive when discussing Kim Jong Un, probably the most repressive ruler on the planet. Trump made clear that he is jealous of the heavily fortified demilitarized zone separating North Korea from South Korea — and preventing North Korean citizens from escaping to freedom. “When you talk about a border, that’s what they call a border,” Trump gushed. “Nobody goes through that border.” Acting as if he were asking a girl on whom he has a crush to meet him at the ice cream parlor, Trump went on Twitter to invite Kim “to meet him at the Border/DMZ just to shake his hand and say Hello(?)!” The United States and North Korea have had hardly any contact since the failed Hanoi summit in February. But no matter: Trump makes clear that his one-sided bromance with Kim remains very much alive.

Asked about his embrace of dictators, Trump told reporters, “I get along with a lot of people.” Not true. He doesn’t get along with America’s democratic allies. Before flying to Osaka, Trump complained that “Europe treats us worse than China” and even claimed that “European nations were set up to take advantage of the United States.” (How prescient of the Europeans to create their nations to take advantage of another country that did not yet exist.) In a telling comment, Trump said, “You have a woman in Europe, I won’t mention her name . . . she hates the United States perhaps worse than any person I’ve ever met.” He was apparently referring to Margrethe Vestager, the European Union antitrust chief. So he thinks Vestager is more anti-American than his pal Putin, who has actually attacked America.

Trump was no kinder to his Japanese hosts, complaining that the U.S.-Japan mutual security treaty is “unfair” because “if Japan is attacked, we will fight World War III. … But if we’re attacked, Japan doesn’t have to help us at all. They can watch it on a Sony television.” As Gary Bass noted in the New York Times, Japan can hardly defend America since Gen. Douglas MacArthur imposed a constitution that abjured war and limited its military to “self-defense forces.” Nevertheless, Japan sent its Self-Defense Force in a noncombat role to help U.S. troops in Iraq.

One might excuse Trump for his ignorance of the intricacies of U.S.-Japanese relations. What’s unforgivable is his ignorance of, and hostility to, the principles that make America great.

Read more:

The Post’s View: Rather than defend democracy, Trump jokes with Putin

Paul Waldman: Trump sucks up to Putin, embarrassing us yet again

Anne Applebaum: Putin’s attack on Western values was familiar. The American reaction was not.

The Post’s View: Trump can’t crumple up history at will

David Ignatius: Trump says war with Iran wouldn’t last very long. He hasn’t read enough history.