Rory McIlroy insists that when the Ryder Cup comes to his native Ireland in 2027, American golfers will not endure the same abuse that he and other members of Team Europe faced this past weekend at Bethpage Black.

“We’ll be making sure to say to our fans in Ireland in 2027 that what happened here this week is not acceptable,” Mr. McIlroy said after Europe retained the Ryder Cup by edging the Americans, 15-13.

Europe withstood a furious Sunday rally from Team USA to win on foreign soil for the first time since 2012 and claim the Cup for the ninth time in the last 12 matches. But the victory was overshadowed by the behavior of a raucous New York crowd that often crossed the line from spirited support to outright hostility, turning golf’s premiere team event into WrestleMania.

Players were taunted and decorum was often abandoned during the three days of competition. Mr. McIlroy, playing in his eighth Ryder Cup, initially blew sarcastic kisses to the hecklers, but the career grand slam winner admitted the heckling got under his skin at times. At one point he refused to putt until the crowd got quiet. Later he told spectators to “shut the f— up” before hitting a brilliant shot that would win a match.

Things turned uglier on Sunday when someone from the gallery at the 17th green threw a drink that appeared to hit a hat worn by Mr. McIlroy’s wife, Erica Stoll, who happens to be American. Viral footage showed Mr. McIlroy tending to his wife as she brushed away tears.

“I don’t think we should ever accept that in golf,” Mr. McIlroy said. “Golf teaches you etiquette, how to respect people, and how to play by the rules. Sometimes this week, we didn’t see that. This should not be what is acceptable in the Ryder Cup. For me, come support your team, but respect the other side as well.”

That message needs to be repeated in the run-up to the 2027 Ryder Cup set for Adare Manor at County Limerick, Ireland. But don’t count on the event returning to the gentlemanly exhibition it was intended to be when conceived 98 years ago.

The message for the last two years was about how loud and passionate the 2025 Ryder Cup would be, played on a municipal course in New York. The American captain, Keegan Bradley, a New England native, and his roster of Americans implored the crowd to be at full throat from start to finish. But what was intended to be a showcase of golf’s best at a storied venue disintegrated into an arena of hostility and vulgarity.

“Cam [Young] and I said to Shane [Lowry] and Rory that we felt for them,” Justin Thomas of Team USA said. “We just wished that we gave our fans something to cheer for instead of people to cheer against.”

Ultimately, the ugly heckling only inspired a dominating performance by Europe, which entered Sunday’s singles competition with what proved to be an insurmountable seven-point lead. No team had ever won from more than four points behind going into the 12 singles matches.

Europe needed just two points to retain the Cup after being awarded a valuable half point when Viktor Hovland of Norway had to withdraw because of a neck injury. According to long-standing Ryder Cup rules, each team is awarded a half-point when one player is forced to withdraw.

“It has to change,” Mr. Bradley later said of the rule. “Nothing against Viktor, but that rule needs to change by the next Ryder Cup.”

There are other changes the American team needs to make before getting to Ireland.  The first might be a change in captains. Mr. Bradley, at age 39, was a controversial choice for a duty normally given to a senior golfer of status.

He made his first gaffe during the opening ceremony, when he misstated that Justin Rose, a member of Team Europe, made the winning putt at Brookline in 1999 instead of American Justin Leonard.

His pairings during the first two days of competition were also questioned, as was the course setup. Bethpage Black is normally a brutal test of tight fairways and tall rough. Instead, the rough was trimmed, and the greens were soft. Team Europe took advantage, making a barrage of birdies during the first two days of foursomes and four-ball.

“Obviously, it wasn’t the right decision,” Mr. Bradley said. “I definitely made a mistake on the course setup. I should have listened to my intuition.”

The Americans also need better performances from their top players. Scottie Scheffler, the no. 1 ranked player in the world, became the first since Peter Alliss in 1967 to go 0-4 in his first four sessions before winning his singles match against Mr. McIlroy.

“It was probably one of the lowest moments of my career,” Mr. Scheffler said after the first two days of competition.

The Americans salvaged some respect on Sunday. They won or halved all but one of the final day’s singles matches, making the final score sound more competitive than it actually was.

Europe, returning 11 of the 12 players who won the Ryder Cup two years ago at Rome, fed off the hostile crowd and won the Cup by dominating the first two days in record-setting fashion.

Tommy Fleetwood, Tyrrell Hatton, Jon Rahm, and Mr. McIlroy all scored at least three points for Europe, while only Cameron Young and Xander Schauffele managed three points for the Americans.

“Future generations will talk about this team and how they were able to overcome one of the toughest environments in all of sports,” the European captain, Luke Donald, said.

Ireland figures to be a tough environment for the American team despite Mr. McIlroy’s early call for civility. The Americans can only hope to do as well playing away from home as the Europeans did. “It was a rough week for all of us,” Mr. McIlroy said. “But at the same time, we shut them up with our performance and how we played.”