On May 31, the same day the Trump Administration announced steel and aluminum tariffs against the European Union, French President Emmanuel Macron placed a call to President Trump. It didn’t go well. Hoping perhaps to draw on goodwill fostered by the congenial time they spent together in Washington in April–just before Trump disappointed Macron by withdrawing the U.S. from the Iran nuclear deal–the French President decided to try some straight talk with Trump on trade. A source explained the outcome to CNN: “Macron thought he would be able to speak his mind, based on the relationship. But Trump can’t handle being criticized like that.”

That’s why the gathering of leaders of the G-7 countries–the U.S., the U.K., France, Germany, Italy, Japan and Canada–in La Malbaie, Quebec, on June 8 and 9 is unusually interesting. The host nation’s Prime Minister, Justin Trudeau, previewed the G-7 meeting as “extraordinarily valuable, because it’s an opportunity for like-minded nations to come together and talk about shared challenges.” Like-minded? Shared challenges? Not with a U.S. President who sees allies as constraints and prefers to get things done by twisting arms and making threats.

Donald Trump made his mark in the cutthroat world of New York real estate the way a tough-minded poker player bullies those at the table with less money to spend. He played as if he had bottomless pockets. The guy who is not afraid to lose a few hands likes to push the stakes, to go all in and to dare those across the table to accept more risk by staying in the game. With that strategy, he won many hands without always holding the best cards or sitting on a fat wallet.

As President, Trump brought this strategy to the table with South Korea and Brazil. When he made trade threats, the governments of those countries knew they could bring the U.S. before the World Trade Organization and (probably) win. But that would take years, and their economies would suffer much damage in the meantime. Instead, they cut deals. And so they figured: Give the bully some of what he wants and maybe he’ll turn his attention toward someone else. (The renegotiation of NAFTA may eventually end in the same fashion.)

But there are limits to this strategy. What happens when someone calls Trump’s bluff? If Kim Jong Un steps into the white-hot spotlight that follows Trump and offers him something tomorrow but nothing today, what does Trump do about it? Launch a strike that risks a war? Call him names? Threaten tariffs on China so it puts more pressure on North Korea?

Furthermore, what happens when Trump discovers he doesn’t have the big advantage he thinks he has? Trump believes (correctly) that if it comes to a trade war, the U.S. economy can withstand more pain than the Chinese economy. But Chinese President Xi Jinping believes (correctly) that Trump is politically much more vulnerable; Xi doesn’t need to win swing states to remain in charge. Sanctions targeted at Trump voters can do more damage more quickly than Trump might expect.

Finally, when you discover you’ve picked a tougher fight than you expected, it’s best to have friends in the room. Like, say, the G-7 allies. But as those meeting with Trump in Quebec during this summit already know, Trump’s “America first” approach is backed by the threat of U.S. power, not the opportunities created by shared values and common interests. Because of this, it’s worth noting the meeting of the Shanghai Cooperation Organization, which will bring Russia, India, Iran and others to China on June 9 and 10. The Europeans, Japanese and Canadians all know that trade with China will be a big part of their future. China may even soon overtake the U.S. as the E.U.’s largest trade partner.

International relations are not a poker game. In a world of “every nation for itself”–a G-zero world–it’s harder than ever to accomplish anything ambitious without allies. Trump’s indiscriminate use of “I dare you to fight” tactics with friends and foes alike is eroding not only traditional alliances but also the institutions those alliances have sustained over many decades. Over the long term, that’s bad for the U.S. and bad for the world.

This appears in the June 18, 2018 issue of TIME.

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