But "Rocket Man," North Korea's Kim Jong Un, is, in fact, a despot with a missile program and pledges to develop a usable hydrogen bomb.

So while the stakes are new and different for President Donald Trump, his tactics remain the same.

What name-calling can get him in a standoff with North Korea is much less clear.

The bellicose US President's bravado should surprise absolutely no one; he picked fights throughout the Republican primary, doling out nicknames to his opponents, then seeking out new adversaries when the foe du jour was vanquished.

That's how we got from "Little Marco," his moniker for Florida Sen. Marco Rubio, with whom he faced off in the primary, to "Crooked Hillary," his name for Democratic nominee Hillary Clinton.

Name-calling, to varying degrees, helped Trump embarrass Rubio in the Florida primary, beat down Cruz on the stump and ahead of what was shaping up to be a tight delegate fight, and destroy the blue wall Clinton was banking on in the Rust Belt -- and Trump knows it. The through-line is clear. He's shown that, when under pressure, he will revert to the tactics that got him this job in the first place.

Trump has a flair for rhetoric and for barbs. His threat of "fire and fury" if North Korea didn't cool it with the missile testing conjured dark images of military power. But it was not effective in deterring Kim from ordering additional launches.

Calling the North Korea leader "Rocket Man" at the UN and threatening to destroy his country if it endangers the US, along with the slapping of new penalties on the already heavily sanctioned nation, was met with a threat from the North Koreans to test a hydrogen bomb over the Pacific Ocean and a riposte that Trump is a dotard

In each case during the campaign, Trump would use a nickname both on Twitter and at campaign rallies, feeding off his crowds, to build support among the faithful, and to drive home the point that his opponent was flawed -- and that he was the alpha dog.

Since taking office, he's squared off against Democrats and also Republicans in Congress on a variety of issues. He'll call out senators over a piece of legislation, like the effort to repeal Obamacare. But he keeps returning to Clinton even though he beat her last November, reveling in the comfort of his unexpected victory.

But Trump is not running against "Rocket Man." There's no simple win-loss calculation to making Kim his personal enemy. He's not trying to vanquish him at the ballot box by impugning his integrity, and he's not trying to get pressure on him to support an agenda.

He's simply trying to get Kim to stop testing missiles and seeking a nuclear weapon. But going on what's happened to date, it's looking more and more like the name-calling has had the opposite effect.

And it could end up being the real difference in Trump's foreign policy, which so far has consisted of removing the US from two large multinational agreements (The Trans-Pacific Partnership and the Paris climate agreement). He has no interest in being leader of the free world, but rather in the economic nationalism he likes to call "America First."

This is the natural progression of Trump from reality star and New York City provocateur to primary candidate and then Republican iconoclast, to now, presumably, leader of the free world.

But there is no new prize for Trump, the presidential name-caller, in a pitched rhetorical battle with a dictator. Winning the rhetorical battle is one thing. But it could be very different than a diplomatic solution to dealing with North Korea.