After all of Trump's diplomatic high jinks, the same problems mount

First there was gunboat diplomacy, a foreign policy supported by the threat of military force.

Then came shuttle diplomacy, where outside parties served as intermediaries between opposing sides.

Now we have experienced repeated bouts of vaudeville diplomacy — even as serious tensions continue to face the U.S.

This week, North Korea's dictator Kim Jong Un talked in a lengthy policy statement about expanding his nation's nuclear force. He vaguely threatened to show off a "new strategic weapon" in the near future and "shift to a shocking actual action."

Reacting to Kim's earlier holiday-surprise threat, President Donald Trump sought to make a what-me-worry joke from Mar-a-Lago.

"Maybe it's a nice present," Trump said. "Maybe it's a present where he sends me a beautiful vase as opposed to a missile test. I may get a vase. I may get a nice present from him. You don't know. You never know."

Whether Trump chooses at a given moment to talk about "fire and fury" or "beautiful letters" or how he and Kim "fell in love," North Korea proceeds by all accounts on the same rogue-state track as before.

Despite risible claims of entitlement to a Nobel Prize, Trump enters a fourth year in office with the same set of challenges as earlier U.S. leaders he derided as failing to confront Kim's threat.

Sometimes the more comical episodes are exceptionally short. Less than five months ago, the president pushed to buy Greenland, the ice-covered autonomous Danish territory.

Greenland's Ministry of Foreign Affairs immediately treated it as a joke. “We’re open for business, not for sale,” officials there said. Danish Prime Minister Mette Frederiksen called the whole suggestion "absurd."

Trump shared a photo-shopped meme of a gilded Trump Tower rising above the rocky landscape, just to promise he would not make this come true.

Sometimes the question is left open as to who the comics and the serious actors are.

Last month, a viral video showed Canadian Prime Minister Justin Trudeau, British Prime Minister Boris Johnson, French President Emmanuel Macron and others huddling at a Buckingham Palace reception related to NATO.

A clearly amused Trudeau alluded to Trump: "He was late because he takes a 40-minute press conference off the top." Trudeau later adds, "I watched his team's jaws drop on the floor."

Suddenly this week, the laughter vanishes.

U.S.-Iran hostilities have flared anew in Iraq — which some experts attribute at least in part to Trump's sneering cancellation of the 2015 multilateral nuclear treaty in which NATO members were involved.

In the Mideast, at least, the heyday for vaudeville diplomacy may already have passed as tensions grow more serious and lethal.

Trump is expected to tout an airstrike near the Baghdad airport that killed Iranian Quds Force commander Qassem Soleimani and another senior Iranian-linked figure as evidence of his seriousness.

That's quite a contrast to his previous suggestions that harsher sanctions had changed Iran's attitude. Back in June, he said: “Look what has happened to Iran. Iran, when I first came into office, was a terror.

"Now they’re pulling back because they’ve got serious economic problems.”

Better rewrite that skit.

By Dan Janison

dan.janison@newsday.comDanJanison

Dan Janison is a member of the Newsday editorial board.