WASHINGTON — We’ve been conditioned by Hollywood to see the president of the United States step up to the lectern to confidently tell us how he will combat the existential threat to the planet — be it aliens, asteroids, tidal waves, volcanoes, killer sharks, killer robots or a 500-billion-ton comet the size of New York City.

So it was quite stunning to see the president of the United States step up to the lectern to declare himself the existential threat to the planet.

And with a calming band playing us to our doom, just like on the Titanic.

You know you’re in trouble when beclouded Beijing, where birds go to die, replaces you as a leader on climate change.

America is living through a fractured fairy tale, in the grip of a lonely and uninformed mad king, an arrogant and naïve princeling, a comely but complicit blond princess and a dyspeptic, dystopian troll under the bridge.