As U.S. President Donald Trump prepares to mark the 75th anniversary of D-Day with a state visit to the United Kingdom and trip to France, political pundits wait with bated breath.

With a spotty record for his diplomatic dealings on the world stage, many wonder what might transpire during such a solemn event.

“When it comes to Trump showing up at events like this, expect the worst,” Steve Saideman, director of the Canadian Defense and Security Network and Carleton University professor, told CTVNews.ca. “He’s going to be obnoxious.”

Though Trump has garnered criticism in Europe before—most notably for cancelling an appearance at a wreath-laying ceremony at a First World War cemetery in France in 2018 due to the weather—experts say any controversy during this visit could place more tension on an already strained relationship between the U.S. and Europe.

“Things are very tense because Trump has issued a number of threats towards the allies, including opting out of the Iran agreement,” explained Saideman.

“People are starting to look at the U.S. as rivals rather than allies.”

Saideman believes tensions between the allies have been renewed over the last four years largely thanks to the Trump administration -- and further escalated in recent months as questions arise about a potential conflict with Iran.

In May, the U.S. Department of Defense deployed additional ships to the Middle East, cautioning that “the United States does not seek conflict with Iran, but we are postured and ready to defend U.S. forces and interests in the region.”

Days later, the president issued a much starker warning on Twitter: “If Iran wants to fight, that will be the official end of Iran.”

Saideman warns that this may feel like deja-vu for many European nations.

“Now we have a new march to war—a war Europeans thought was avoidable because of the Iran arms deal,” he explained. “They fear they are going to be dragged into another war, but they are less likely to go to war with this administration.”

Careful not to personalize policy, expert warns

While some feel that Trump’s personal politics may get in the way of international relations, others argue it may give him certain advantages.

“It’s impossible to have a rational assessment of the issues of policies unless one is able to separate the personality from actual politics. This is a president who is bombastic, vulgar, has issues with factual accuracy,” Aurel Braun, professor of international relations and political science at the University of Toronto told CTVNews.ca. “[But] we tend to personalize policy.”

Braun noted that Trump and his administration have been incredibly vocal in their dissatisfaction regarding EU defence spending under the NATO agreement -- a tactic that he says is valid.

“Trump has been more confrontational, but he’s making more progress than Obama, for example,” explained Braun.

“You have a wealthy country like Germany that has spent 1.3 per cent of their GDP on defence. It’s a perfectly appropriate question for Mr. Trump to ask why European protection should be more important to the U.S. than Europe. In his obnoxious way, he has been speaking truth to power.”