BERLIN — “What?!”

The headline on the cover of Germany’s Stern magazine this week under a photograph of a surprised-looking Boris Johnson captured the sentiment across the European Union that the new prime minister has built his career on seeking to undermine.

While Americans seem unsure what to make of the new British prime minister ("He's known for making very funny, highly literate, very smart speeches,” a correspondent for U.S. National Public Radio explained to listeners Tuesday, adding that he went to Eton and Oxford and is “absolutely one of Britain’s elite”), Europeans have no illusions about who Johnson really is.

Across the Continent, the reaction to his ascension to the U.K.’s highest political office has been marked more by gallows humor than genuine concern about what his tenure might bring. From Brussels to Berlin, everyone seems to have a personal "best of Boris" list.

There was that time he got fired from the Times for making up a quote about Edward II’s purported pubescent lover. And how about the piece he wrote in the Telegraph a few years later (“Italy fails to measure up on condoms”) in which he falsely claimed that Rome had tried to convince the EU to revise its rules on condoms to accommodate smaller penises? Remember that video of Johnson lunging headlong into the privates of former German national football player Maurizio Gaudino during a charity match?

While Europeans may take delight in lampooning Donald Trump, they also respect (and fear) the power of his office. But no one’s afraid of Johnson.

Even in a political landscape accustomed to the likes of Silvio Berlusconi and Viktor Orbán, Johnson’s outrageous style and Conwayesque relationship with facts make him stick out like his trademark cowlick. But as he showed during his campaign to become prime minister, whether by using a vacuum-packed “kipper” as a stage prop or guzzling beer, Johnson is more than happy to be seen as a clown.

His biggest challenge in dealing with the EU in the coming weeks and months will be to prove there’s more in his repertoire.

But after building a political persona over decades based on caricaturing Europeans as humorless rubes, Johnson may soon discover that the targets of his comedy can’t see beyond the joke.

After years of laughing at him, Europeans simply don’t take Johnson seriously. At this stage, it’s difficult to imagine what could change their minds.

While Europeans may take delight in lampooning Donald Trump, they also respect (and fear) the power of his office. Whether they like it or not (and most don’t), Trump has considerable leverage over Europe, both in terms of the economy and security.

But no one’s afraid of Johnson.

Though the U.K. remains a key strategic player within Europe, that reliance cuts across both sides of the Channel. Following the seizure of a British-flagged oil tanker by Iran last week, for example, the U.K. responded by calling for a European naval force to protect sea routes in the Strait of Hormuz.

When it comes to the economy, the U.K. is far more dependent on the EU than vice versa.

That’s why Europe’s response to Johnson’s threat to leave the EU come what may on October 31, deal or no deal, has been a polite yawn.

If anything, Johnson’s election as prime minister will make it easier for EU leaders to stick to their guns by refusing to budge on the terms of the deal they negotiated with Theresa May, his predecessor. Whatever her shortcomings as a prime minister, May, unlike Johnson, enjoyed a reputation among European leaders as an honest broker.

Given the leading role Johnson played in the Brexit campaign and his continued taunting of the EU, European leaders don’t just distrust the new prime minister, many despise him.

The danger of Johnson’s credibility gap is that it could prompt EU leaders to underestimate his willingness to drive Britain off the Brexit cliff, triggering a potentially catastrophic chain reaction.

Johnson’s boosters predict he’ll rise to the historic challenges Britain faces, much like his idol, Winston Churchill. Like Johnson, Churchill also met with deep skepticism when he became prime minister and was viewed as a loose cannon, even reckless.

Yet that would appear to be where the similarities end.

Not even Churchill’s political enemies doubted his conviction to his ideals. In Johnson’s case, it’s hard to find anyone who thinks he even has any.

Even if Johnson’s comedic talents have earned him considerable attention (and, arguably, the keys to Downing Street), Europe’s leaders are determined to have the last laugh.