Trump was completely embarrassed on the first day of the NATO summit, and it shows no one is bothering to take him seriously anymore

• President Donald Trump is at the second day of the NATO leaders' summit in England.
• He entered the conference on Tuesday triumphant and claiming credit for the defense alliance's budget changes.
• But that success waned quickly as the day went on, as French President Emmanuel Macron openly questioned his claims, Canadian Prime Minister Justin Trudeau mocked him behind his back, and UK Prime Minister Boris Johnson refused to be photographed with him.
• All of these leaders had been openly diplomatic and friendly with Trump in the past. Their behavior on Tuesday shows the world is no longer bothering to take the US president seriously.
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President Donald Trump entered the NATO summit triumphant, claiming credit for large structural changes in the alliance's defense spending.

But his first day turned out to encompass one embarrassment after another, with multiple world leaders openly sparring with him and mocking him behind his back - showing that nobody is bothering to take him seriously anymore.

Shortly before meeting other Western leaders in London on Tuesday, Trump claimed credit for NATO reducing the US government's contributions to the group, and increasing those from other allies.

Though this plan had been in place since 2014 - when Barack Obama was president - Trump took it as a personal victory because he had long railed against what he perceived as the US' outsized contribution to the defense alliance.

That feeling of triumph likely waned quickly, though, as the day went on. Here's a rundown of Trump's numerous embarrassments on Tuesday:

• He was publicly fact-checked by French President Emmanuel Macron - with whom he has touted having a strong relationship - at their joint press conference. Macron said that ISIS had not yet been defeated, despite Trump's repeated insistence that it had.
• Macron also challenged Trump's claim that ISIS fighters were "mostly from Europe."
• At a separate press conference with Canadian Prime Minister Justin Trudeau, Trump openly questioned one of NATO's founding principles - Article 5, which requires members to protect each other if under attack - prompting concern and criticism among NATO officials.
• Retired US Army Gen. Wesley Clark, a former NATO commander, told Business Insider's David Choi that Trump's comments were "a very rough way to play" with the alliance's principles, and that "it undercuts deterrence, encourages potential adversaries, and erodes NATO itself."

• Trump was roundly mocked by world leaders and royalty behind his back. Trudeau was recorded on video telling Macron, UK Prime Minister Boris Johnson, Dutch Prime Minister Mark Rutte, and Princess Anne poking fun at Trump's impromptu 40-minute press conference, prompting their laughter.
• The British Conservative Party took great pains to distance Johnson from Trump while the two leaders were in the same vicinity, for fear that Trump would jeopardize its chances of winning the upcoming UK general election next week. (Trump did appear to honor this by saying on Tuesday morning he had no comment on the election.)
• According to Politico's London Playbook, Johnson was "so keen not to be photographed with the U.S. president that he did not even greet him at the door when he and wife Melania arrived" at 10 Downing Street on Tuesday night.

This all shows world leaders aren't bothering to take Trump seriously anymore.

Macron's publicly schooling Trump in front of dozens of reporters is a far cry from the two leaders' apparent "bromance" two years ago.

Trudeau's willingness to mock Trump in front of other world leaders contrasts heavily with the Canadian prime minister's pledge to himself in 2016 to only criticize the comments, rather than the character, of his American counterpart.

"There was a discipline that I imposed on myself early," Trudeau had told Canadian Broadcasting Corporation journalist Aaron Wherry, who wrote a book about the prime minister.

Johnson's refusal to be publicly seen with Trump also comes as a huge snub to the US president, who in October had endorsed him in the upcoming election.

George Conway, the husband of senior White House counselor Kellyanne Conway, tweeted in response to the video showing world leaders laughing at him on Tuesday, saying that Trump is "the laughing stock of the planet."

"The world thinks you are an incompetent, ignorant, dumb, deranged buffoon - and they are right," Conway continued. "And you prove it to them every day."

Trump, on his end, has put on a veneer of success at the NATO summit on his social media accounts. It remains unclear how long that will last.

• Read more:
• Trump's demands for NATO is a 'very rough way to play,' a former top commander of the alliance says
• Video shows world leaders mocking Trump after uncomfortable first day at NATO summit
• Trump went off at the NATO summit with wild comments about climate change, ISIS fighters, and Adam Schiff
• The NATO summit started as uncomfortably as expected, with Trump slamming Macron's 'very, very nasty' statement on the group being brain-dead