SAITAMA, Japan—Kevin Durant had every reason not to be here. 

He already had two Olympic gold medals. He gritted his teeth through a grueling NBA schedule condensed by the pandemic as he was coming back from a torn Achilles tendon. He would have the chance to sign a nearly $200 million contract extension with the Brooklyn Nets during the Olympics, and he knew the Tokyo Games would come with draconian restrictions that make the whole experience as pleasant as week-old sushi.

But now as he flies out of Japan, his luggage will contain the souvenir that made it all worth it: yet another Olympic gold. His decision to ignore all of the arguments to take a summer vacation and play in his third Games anyway proved to be monumentally important. 

The difference between the Americans and the rest of the world used to be an entire team of superstars. Now the narrow gap is filled by one skinny guy named Kevin.

“This is one of those special journeys that is hard to describe,” Durant said. “A lot of people said it was going to be tough for us to win. And to be honest, they really don’t matter.”

Kevin Durant won his third gold medal.

Photo: Gregory Shamus/Getty Images

The Americans won their fourth straight Olympic gold in men’s basketball Saturday at Saitama Super Arena when they topped France 87-82, and it’s impossible to look at the recent history of international basketball without thinking how it would be unrecognizable without this one player. 

His teammates say that the squad revolves around him. His opponents even concede he can make the Americans impossible to beat. Durant has kept the U.S. a step ahead when every other country has been catching up faster than ever.   

“I think these games are really meaningful to him. We feed off his energy,” Portland Trail Blazers guard Damian Lillard said. “He didn’t have to be here.”

Durant’s performance in Japan simply polished his résumé as the greatest U.S. Olympic men’s basketball player ever for the country that has dominated the sport. He is Team USA’s all-time leading scorer. He is only the second American with three Olympic golds in men’s basketball. And unlike Carmelo Anthony, the other player with three, Durant was the linchpin of his teams. 

Durant’s performance in Japan simply polished his résumé as the greatest U.S. Olympic men’s basketball player ever.

Photo: Pan Yulong/Zuma Press

At the heart of Durant’s brilliance on the international stage is a curious mix of youth and longevity. He’s young enough to still be a superstar with a body that can withstand the toll of another Olympics. He’s old enough that he was once a member of the Seattle SuperSonics.

Durant has shown year after year that he can be unstoppable over an 82-game season—even after suffering basketball’s worst injury. But what’s remarkable about his exploits with the national team is that the format of the Olympics theoretically favors the underdog. With a group stage followed by three knockout rounds, there is almost no room for error. It’s more like the NCAA tournament than the NBA playoffs. But when every game feels like a Game 7, Durant steps up.

“He’s been the best player in the world,” said Team USA assistant coach Steve Kerr, who won two titles with Durant during his time with the Golden State Warriors. “He’s the guy who’s cool under pressure, hits the big shots, hits the big free throws, does whatever you need.” 

Durant scored 29 points to catapult the U.S. out of an early deficit against France, and this was nothing unusual for him. By his own lofty standards, in fact, it was slightly disappointing. He scored 30 points in the 2016 gold medal game over Serbia. He also scored 30 in the 2012 gold-medal nail-biter against Spain.

It’s easy to see Durant’s outsize impact when he’s on the court. It’s even easier when he’s on the bench. The one game Team USA lost at this tournament was also the first Olympic loss of Durant’s career, and there wasn’t much he could do to stop it. Stuck in foul trouble early during the first matchup with France, he could only watch as the American offense ran into France’s towering defense. 

Les Bleus knew things would be different this time around, and they did everything within their power to find a way to stop him. They were well-equipped to do so. France’s best player, center Rudy Gobert, happens to know a bit about shutting down superstars as a three-time NBA defensive player of the year. Gobert, afterward, conceded there was nothing they could have done: “We knew he was going to do his thing,” he said. “And he did.”   

“We tried to make things tough on him. We tried to make him work as hard as we can,” Gobert said. “But he’s Kevin Durant.” 

Kevin Durant and Jerry Colangelo chat after the medal ceremony.

Photo: Kevin C. Cox/Getty Images

Durant, 32 years old, wasn’t just Team USA’s savior. He was also its caretaker. After the Americans settled for bronze in the 2004 Athens Olympics—a finish considered a crisis for U.S. hoops—he was the final cut from the 2008 “Redeem Team” roster. But he has been a member of every Olympic squad since then and his commitment to the national team has outlasted an entire age bracket of NBA superstars. The likes of LeBron James and Chris Paul, key members in 2008 and 2012, didn’t participate five years ago—or in 2021. 

USA Basketball managing director Jerry Colangelo has long had a sense that Durant would eventually be the player to rebuild the Olympic basketball program around. In the wake of the Athens fiasco, when Durant was an even skinnier freshman at the University of Texas, Colangelo invited him to his first U.S. camp. 

“He was wide eyed, bushy tailed,” Colangelo remembers. And when Colangelo asked, the freshman gave him the answer that would redefine Team USA for a generation.

“I’ll be there,” Durant said. 

Write to Andrew Beaton at andrew.beaton@wsj.com and Joshua Robinson at Joshua.Robinson@wsj.com