We wondered why Trump was behaving like he is, but now we know: it's all about revenge

Second-guessing the sober judgement of history from the state of wild intoxication we reel under today is an imbecile’s game. Being one, I offer this prediction.

When the dust has settled on the Trump era (assuming the dust isn’t so lethally radioactive that no one survives to do the judging), historians will identify 30 April 2011 as the day when history turned.

It would be easy to misidentify the historic moment: that was the day Barack Obama sanctioned the hit on Osama bin Laden.

Yet the assassination looks a trivial event compared with what immediately preceded it. A few hours before his Situation Room vigil began, Obama hilariously dissected an onlooking Donald Trump at the White House Correspondents’ Association dinner.

If you’ve never seen that stand-up turn and want to YouTube it, be warned: your laughter will turn to sobs of despair. Trump’s rigid expression of red-cheeked, white-hot rage as the room erupted at the gags – birtherism, The Apprentice, him adorning the White House roof with the Trump logo – isn’t as gratifying now.

I and many non-imbeciles have wondered before if Trump took a far more monumental decision that night than Obama’s about bin Laden. Was that the moment he resolved to become President purely to punish Obama by dismantling his legacy?

With each week that passes, it is more certain that it was. The longer it hurtles towards wherever it’s headed, the more transparently this festering excrescence of a presidency is revealed as a monstrous revenger fantasy brought to life.

Identifying a pattern in Donald Trump’s policies may seem a bigger fool’s game than anticipating history, but they have this one connecting factor. Every stance he takes is designed to unstitch a panel on the tapestry Obama so patiently created.

Trump was for universal healthcare before he was passionately against it. In the alternate universe where Obama prevented Americans getting health insurance, President Donald J Trump would be obsessed with giving it to them.

Whatever the guy who ridiculed him at the dinner did, Trump’s craving for payback dictates he undo. If this Thanksgiving he takes a carving knife and slits the turkey from ear to ear, safely put it down to Obama having always pardoned the turkey in keeping with tradition.

The latest chapter in the scariest vengeance tale ever told concerns Iran. After withdrawing from the Paris climate change treaty, the frenzied attacks on Obamacare and so on, Trump wants to remove the US from the non-nuclear deal Obama (and other western leaders) struck with the theocracy; the one every sane and informed voice agrees is working as planned.

In Trump’s defence, it’s not as if there’s a recent example of how a paranoid regime will respond to what it sees as an existential threat. But even if there were one, for example’s sake on the Korean peninsula, what difference would it make? Obama did the deal with Iran. Obama made people laugh at him. Ergo, the deal must die.

For now, Trump will probably be denied. The other western signatories are happy with the deal, and it’s up to Congress whether or not to reintroduce the kind of punitive sanctions that would probably tempt Tehran to take the centrifuges out of storage.

The danger of a military strike on North Korea, on the other hand, is clearer and more present than ever. In keeping with the reality TV tone that makes it all such fun, Trump has tweet-trailed the next exciting episode.

“Presidents and their administrations have been talking to North Korea for 25 years,” he writes, “hasn’t worked … Sorry, but only one thing will work!” Asked what that one thing might be, Trump contented himself with: “You’ll figure that out pretty soon.”

Now that may be no more than the latest hand in his ongoing game of bluff with that brinksman supreme, Kim Jong-un. So long as he’s in charge of the military troika which effected a nursery coup in the summer, he will probably be steered clear of the cataclysmically crazy. Generals Kelly, Mattis and McMaster, along with Secretary of State Rex Tillerson, can together subvert his urge to attack Pyongyang and risk a counterstrike against the 10 million people some 35 miles the other side of the border in Seoul.

But Tillerson refuses to deny calling Trump “a moron”, while chief of staff John Kelly is rumoured to be on the verge of resigning. Trump kicked him off Air Force One on Thursday in dudgeon that didn’t seem notably low.

As with all Trump hires, it was always a matter of when rather than if they would terminally displease their boss, or discover the limits of their endurance. What follows if he replaces them with ideological warmongers, in the mould of Steve Bannon, or the theatrically maniacal John Bolton doesn’t bear contemplating.

In the absence of Robert Mueller finding a Kalashnikov so smoking hot that Russian collusion abruptly curtails this presidency, perhaps the world’s best hope still lies with Obama. If he could convince Trump of an epiphany – that he now sees launching a massive strike against Pyongyang and abandoning the Iran deal as the only way ahead – Trump would invite Kim Jong-un to Camp David for an all-you-can-eat artisan French cheese buffet-cum-peace summit.

Yes, of course, this would be the crudest child psychology known to humanity. But when you’re dealing with the crudest child on the planet, and the Doomsday Clock is ticking down from two and a half minutes to midnight, what can there possibly be to lose?