An optimistic take on Donald Trump’s historic meeting Tuesday with Kim Jong Un is that it’s Geneva Redux — a reprise of the 1985 summit between Ronald Reagan and Soviet leader Mikhail Gorbachev that led within a few years to the end of the Cold War.

Let’s hope so. Because another take is that it’s the Plaza Redux, meaning the 1988 real estate debacle in which Trump hastily purchased New York’s Plaza Hotel because it looked like an irresistible trophy, only to be forced to sell it at a loss a few years later as part of a brutal debt restructuring.

The case for Geneva Redux sees parallels between Trump and Reagan — Republican presidents whose hawkish rhetoric and ignorance of policy details disguised an inner pragmatism and visionary imagination.

Could the Soviet scenario unfold with North Korea? Probably not — for reasons that would have been obvious to most conservatives before their current Trump derangement.

First, Trump isn’t Reagan. Reagan generally acted in concert with allies. Trump brazenly acts against them. Reagan’s negotiation method: “Trust but verify.” Trump’s self-declared method: “My touch, my feel.” Reagan refused to give in to Soviet demands that he abandon the Strategic Defense Initiative. Trump surrendered immediately to Pyongyang’s long-held insistence that the U.S. suspend military exercises with South Korea while getting nothing in return. Reagan’s aim was to topple Communist Party rule in Moscow. Trump’s is to preserve it in Pyongyang.

Second, Kim isn’t Gorbachev. Gorbachev was born into a family that suffered acutely the horrors of Stalinism. Kim was born into a family that starved its own people. Gorbachev rose through the ranks as a technocrat. Kim consolidated his rule by murdering his uncle, half brother and other unfortunates. Gorbachev came to office intent on easing political repression at home and defusing tensions with the West. Kim spent his first six years doing precisely the opposite.

Third, Kim knows what happened to Gorbachev, whose spectacular fall served as a lesson to dictators everywhere about the folly of attempting to reform a totalitarian system. Kim may pursue a version of perestroika to stave off economic collapse, but there will be no glasnost. The survival of his regime depends domestically on state terror and internationally on his nuclear arsenal. He will abandon neither.

Fourth, the timetables are incompatible. Trump wants a foreign policy “achievement” by the midterms, and maybe a Nobel Peace Prize sometime before the 2020 election. Kim plans to be ruling North Korea when one of Chelsea Clinton’s kids is president. Trump’s incentive will be to make concessions up front. Kim can renege on his promises much later.

Fifth, Trump is a sucker. Kim is not. Say what you will about the North Korean despot, but consolidating power in his vipers' nest regime, fielding a credible nuclear arsenal, improving his economy without easing political controls, playing nuclear brinkmanship with Trump and then, within weeks, getting the prestige of a superpower summit are political achievements of the first order. Machiavelli smiles from the grave.

As for Trump, the supposed success of the summit after the debacle in Quebec appeals to innate love of drama. He is where he loves to be: at the center of a stunned world’s attention.

But he is also in the place where he always gets himself, and everyone else in his orbit, into the worst trouble: panting for the object of his desire. That’s been true whether it’s the Plaza Hotel, Stormy Daniels and now the “ultimate deal” with Pyongyang.

I’d be happy to be proved wrong. For now, however, it’s hard to see what the Singapore summit has achieved other than to betray America’s allies, our belief in human rights, our history of geopolitical sobriety and our reliance on common sense. For what? A photo op with a sinister glutton and his North Korean counterpart?

Bret Stephens is a columnist for The New York Times.