(CNN) Presidents Donald Trump and Emmanuel Macron just didn't want to let one another go.

The young, globalist French leader and the "America First" commander-in-chief, who are opposites in many ways, put on an extravagant show of friendship Friday on Bastille Day on the Champs-Élysées.

The highlight of a chummy two-day visit was an extraordinary, on-the-walk handshake across the cobblestones, that included multiple mutual pats on the back of the hand and shoulder taps. At one point, the 30-second embrace drew in Macron's wife, Brigitte, leaving first lady Melania Trump standing slightly awkwardly to the side.

The unusual show of personal chemistry in Paris might just mean Macron, 39, and Trump, 71, just got along famously.

But Macron also clearly has a plan by making such an effusive show of friendship toward Trump, even though the US leader is unpopular in Europe and dismayed the French government by pulling out of the Paris climate accord.

It reflects the French leader's desire to ensure the United States does not totally divorce itself from the rest of the West.

And the charm offensive is the latest sign that some world leaders think the best way to get to Trump is not to rebuke or lecture him, but to flatter him and show him respect.

So France laid on sumptuous gastronomy, in a restaurant billed as "infused with dreams and magic" inside the Eiffel Tower. They provided a tour of Napoleon's tomb and made Trump guest of honor at the Bastille Day parade with marching bands, tanks and flyovers.

On Friday, the fast growing bond between Macron and Trump was on display in a prolonged handshake, as each man patted the other's shoulders at the end of the day's celebrations.

As he wrapped up his trip, Trump showed how much he appreciated the hospitality, tweeting a picture of he and Macron, heads close together, deep in conversation as they watched the parade with the Arc de Triomphe in the background.

"It was a great honor to represent the United States at the magnificent #BastilleDay parade. Congratulations President @EmmanuelMacron," Trump wrote.

It was a great honor to represent the United States at the magnificent #BastilleDay parade. Congratulations President @EmmanuelMacron! pic.twitter.com/1J4vZiy98y — Donald J. Trump (@realDonaldTrump) July 14, 2017

It's entirely possible that Trump and Macron have developed a genuine bond. But Trump's recent foreign trips to other nations in urgent need of US support have seen similar displays of pomp.

In Saudi Arabia, the President found his image projected on the wall of his hotel, got the reddest of red carpet welcomes, a sword dance, and went home with a gold-chained necklace bearing the kingdom's highest honor.

"Words do not do justice to the grandeur of this remarkable place and the incredible hospitality you have shown us from the moment we arrived," Trump told Saudi King Salman.

In Poland, the drill involved busing in a friendly crowd to cheer at Trump's campaign-style lines embedded in a major foreign policy speech, countering ideas that Europe abhors the new US President.

"It's a majestic nation, it really is, it's a spectacular place, some of the most beautiful sights," Trump said.

The first leader to notice the President's appreciation for exaggerated shows of respect might have been Japanese Prime Minister Shinzo Abe.

Even before Trump was inaugurated, he showed up at Trump Tower with a gold-plated golf driver -- and has since carved out a good relationship with the President.

For sure, most countries tend to turn up the pageantry when Air Force One swoops into town -- no matter who is commander-in-chief.

But Macron, Polish President Andrzej Duda and the Saudi royals went the extra mile for a president who knows how to put on a show.

It's not hard to work out why.

The Saudis fretted for years over their relationship with the Obama administration and its pursuit of a nuclear deal with their arch-enemy Iran. Now they have a new friend in the Oval Office.

Duda's right-wing government shares some of the populist impulses of the Trump administration and suspicion of bureaucracy in the EU. It has tried to impress on Trump the need to keep an eye on Russia's territorial maneuverings in the East.

Macron, the rising star of European politics, is playing a subtle diplomatic gambit.

While not disguising his dismay at Trump's exit from the Paris climate accord, he's trying to bolster his own image as a statesman and set himself up as a bridge between Trump and Europe.

Merkel goes in the other direction

Flattery isn't everyone's game, though.

German Chancellor Angela Merkel tried to make a connection with Trump -- but her body language alongside the President in Washington was awkward, with the two famously not shaking hands in front of cameras in the Oval Office.

Merkel invited his daughter Ivanka to Germany, seeking a channel to the mercurial President.

But after Trump's first visit to Europe in May, Merkel warned that the continent could no longer totally rely on the US following his lukewarm remarks about NATO.

And following Trump's pullout from the Paris climate accord, Merkel's husband had arranged for spouses at the G20 in Hamburg to visit a climate change research lab. (Melania Trump was unable to attend due to protests that heightened security in the city.)

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Worry about backlash?

Some leaders have more to consider when feting the unpopular US President than others.

The Saudis, with their iron rule, don't have to worry about a backlash.

Macron, thanks to decisive presidential and parliamentary election wins, is the most secure French president in years.

But Merkel is running for re-election in September and must keep an eye on her her left flank, where hostility toward Trump is intense.

Another foreign leader, Britain's Theresa May, also tried to pal up to Trump. But photos of her holding his hand at the White House mushroomed into a political disaster back home.

After her election debacle, where she barely held onto her job as Prime Minister, Trump's visit to London, seen as an early bid to wow him with pageantry fit for a Queen, and a President, is now delayed until next year.

Some leaders have also worked out that the better they treat Trump, the nicer he is to them.

"He's a friend of mine. I have great respect for him," Trump said of China's Xi Jinping Thursday. "He's a very talented man."

Before meeting Abe in Italy in May, Trump said, "we've got a great friendship."

The President is already getting up close and personal with Macron. "We have a very good relationship, a good friendship," Trump said in Paris, on a day when he affectionately patted his younger counterpart on the back.

Macron however, perhaps mindful of Trump's rock bottom approval ratings in France, kept things a little more formal.

"I never very much want to comment who we are and what we are doing personally," he said.

"But I can tell you that this evening at the Eiffel Tower, it will be a dinner between friends. Because we are the representatives of two countries that have been allies forever."

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What does the US get?

Some experts however fear Trump's head is turned a little too easily.

"The Saudis dazzled Trump's inexperienced negotiators with attention, arms deals and donations to World Bank fund for women that Ivanka Trump is championing," said CNN's Fareed Zakaria in May.

"In short, the Saudis played Donald Trump. America has now signed up for Saudi Arabia's Middle East policy -- a relentless battle against Shiites and allies in the region."

Abe's courtship also seemed to work.

The Japanese delegation was surprised when it turned up in Washington for the first summit with the President in February and there was no talk of Trump's demands for Tokyo to pay more of the cost of US troops stationed in Japan.

Xi's efforts seem to have put a looming trade war with Trump on hold -- and there's little evidence that Beijing has effectively reined in North Korea's missile and nuclear program as the President wants.

Macron may be playing a longer game, enhancing his own status and that of his nation by getting in the President's good books.

What is not known yet, after all this global flattery, is what America is getting in return.