Carla Sands, who is now the U.S. ambassador to Denmark, in Los Angeles in December 2014. (Jonathan Leibson/Getty Images for The Music Center)

Dennis Jett, a former career diplomat who served as ambassador to Peru and to Mozambique, is a professor of international affairs at Penn State University and is the author of “American Ambassadors: The Past, Present and Future of America’s Diplomats.”

When relations with a traditional U.S. ally hit a rough patch, it is always good to have a capable ambassador on the scene to attempt to smooth things over. One who has extensive experience in dealing with subluxation, for instance, can help get the bilateral relationship realigned in no time.

Wait. What?

Well, if it’s as some chiropractors believe and a subluxated spine is the root of all illness, couldn’t it also perhaps be the key to working out a diplomatic spat? One has to hope, as the let’s-buy-Greenland brouhaha in the United States’ relationship with Denmark is being left to an ambassador whose résumé is devoid of governmental or international experience. She did, however, work as a chiropractor before marrying a now-deceased multimillionaire — and as a soap-opera and B-movie star. Who can ever forget her role in “Deathstalker and the Warriors from Hell”?

Ambassador Carla Sands, whose generous donations to Donald Trump no doubt brought her to the attention of the White House Personnel Office after his election, is not unique in her experience. Her predecessor, appointed by President Barack Obama, had been a Hollywood actor and had his own reality TV show as ambassador. In fact, of the 20 men and women who have served as our ambassador in Copenhagen over the past 60 years, only two of them were career diplomats. The Danes are used to envoys with, to put it diplomatically, interesting backgrounds.

The selling of certain ambassadorships is as much a time-honored tradition entrenched in both political parties as it is thinly veiled corruption. Even Congress’s explicit intervention — a 1974 law saying ambassadorships should go to non-career diplomats only in exceptional circumstances and never with regard to political contributions — didn’t dismantle it. Before the law, noncareer appointees made up about 31 percent of the ambassadorial nominees. After it was enacted, the figure dropped to 30 percent.

Those in the 30 percent are not distributed randomly around the world, either. In Western Europe and the Caribbean, non-career ambassadors fill about 80 percent of the top diplomatic posts. The rich countries and tropical paradises go to the political appointees; the sweaty and dangerous countries of the world are left almost entirely to the career diplomats.

Whether Trump’s percentage clocks in at the benchmark 30 percent will not be clear until the end of his first term. But one thing is clear. Trump, the ultimate transactional president, will likely end up charging more for ambassadorships than any of his predecessors.

Sands coughed up $750,000 for various Republican causes over the years before being bestowed the title — a record figure for the ambassadorship to the small Scandinavian country. The amount was made possible when Trump opted not to place a limit on how much money people could contribute to his inauguration, in contrast with Obama’s $50,000 maximum. And now, Republican high-rollers and bundlers who didn’t jump aboard the Trump train for its first improbable trip are reaching deep into their pockets to finance his reelection. As one former Republican finance chairman observed, “There’s a huge trove of people who want to be ambassadors, and they are going to belly up to the bar.”

The United States is the only supposedly serious country that hands out large numbers of ambassadorships as party favors. Other nations know that diplomacy is more than endless cocktail parties and not paying parking tickets. Running an embassy requires managing a complex organization for which performance is not measured simply by how much money is made. And understanding the domestic political scene entails more than rubbing elbows with a few local celebrities. Underestimating the task puts the United States at a strategic disadvantage.

Of course, with a president such as Trump, perhaps it doesn’t matter whether ambassadorships are sold to the unqualified rich. He abruptly canceled his planned state visit to Denmark after his grand idea about acquiring Greenland was rejected as "absurd" by the country’s prime minister, Mette Frederiksen. Even a top-flight diplomat would be flummoxed. But if Trump had bothered to ask — and if there had been an ambassador capable of answering (or savvy enough to preempt the president’s question) — the reaction to his proposal to buy Greenland could have been predicted.

As it was, Sands was still ginning up excitement for the trip even on the verge of its cancellation. At a State Department news conference Wednesday, a reporter wondered whether it wasn’t worrisome the ambassador was unaware of the president’s travel status. Didn’t she tweet about the trip just two hours before?

“She did, yeah,” the department spokeswoman said. “That just I think goes to show the strength of the relationship that our ambassador has with the government and they’ll continue to work together.”

Read more:

J.J. McCullough: Think Trump sounds absurd on Greenland? Canada has entertained crazier ideas.

Dana Milbank: The U.S. must take Greenland by force!

Alexandra Petri: The Emperor’s New Island, a tale of Trump buying Greenland

Eugene Robinson: Trump is melting down. Again.