Through no fault of their own, the athletes who will march in massed, joyful ranks behind their nations’ flags in Friday night’s opening ceremony for the first Olympic Games in South America shoulder expectations beyond their own ambitions for gold, silver, bronze and personal bests.

No Olympics in recent memory has opened under so many dark clouds, both within recession-battered Brazil and beyond. Headliners Usain Bolt and Michael Phelps are back for more medals. But no feat of theirs, or the other 10,500 Olympians, between the first medal awards on Saturday and the Aug. 21 closing ceremony will paste over recent horrors of 84 people murdered with a truck in Nice or the shooting massacre of 49 people in a Florida nightclub. Sports are, and always will be, trivial compared to such atrocities that have come depressingly thick and fast of late.

“The Olympics may help me take my mind off things,” said Parisian lawyer Remy Durand, reflecting over lunch Thursday on the Champs-Élysées. “But it’s not going to change my overall mood lastingly, after the attacks in recent weeks and months in France.”

Yet Olympic organizers can’t be faulted for trying, with their “Together we can change the world” slogan and OlympicPeace hashtag. Cold War boycotts aside, the games remain a symbol of global togetherness, even if an increasingly commercialized one. By putting religion and politics aside, the Olympics still can remind the world’s people of their shared humanity.

On Friday, at the opening gala of these Olympics at Rio’s Maracana Stadium, 10 refugee athletes will march as one team behind the white Olympic flag — a reminder to the world that they aren’t solely defined by their lack of a place to call home. While not as grand as opening ceremonies past, Rio still expects to wow.

“The Athens ceremony was classic, and Beijing was grand, was musical. London was quite smart. We’re going to be cool,” said creative director Fernando Meirelles.

Still, the games have their naysayers. Doping scandals — from sprinter Ben Johnson losing his 1988 Olympic gold medal over steroids to Russia’s recent state-organized subversion of anti-doping efforts — have stained all Olympians and heightened cynicism of their feats and worth.

On behalf of all of this summer’s competitors, a Brazilian athlete will pledge at the opening ceremony that they will compete “without doping and without drugs, in the true spirit of sportsmanship.” The same promise has been made at all games since 2000 but may ring false among fans, especially with Russia’s flag fluttering among the others; the International Olympic Committee rejected calls for a blanket ban on all Russian athletes. The IOC, as it has in the past, will store some 4,500 drug-test samples to be taken during these games, so they can be thawed out and retested in years to come.

Then there’s the expense of the games. Big spending and the waste of unused venues in ex-host cities have forced Olympic organizers onto the defensive and left them with a shrinking pool of taxpayers willing to foot the bills. The $10 billion to $12 billion spent on Rio’s games should have gone to better causes in a city rife with poverty, critics say.

After Rio, the Olympics rumble to Tokyo in 2020, leaving Rio de Janeiro’s 6.5 million people — the racially mixed, socially divided “Cariocas” — with the same concerns the world was largely oblivious to before the Olympic echo chamber turned the Zika virus and favelas into household words.

Few outside Brazil cared about untreated sewage and teeming viruses in Rio’s picture-postcard Guanabara Bay before its polluted waters were chosen for Olympic swimming and sailing. Rio’s alarming murder rate and turf wars between drug lords and police weren’t so high on the globe’s agenda before athletes and hundreds of thousands of Olympic visitors discovered that the prospect of being in harm’s way has long been the darker flip side of Brazilian Samba, carnival and caipirinha cocktails.

Despite the problems, Olympic ideals aren’t dead. Pope Francis told pilgrims on Wednesday at his weekly audience at the Vatican that in a world “thirsty for peace, tolerance and reconciliation,” he hopes the games can inspire everyone to pursue a prize that is “not a medal but something more precious — achieving a civilization in which solidarity reigns, founded on the recognition that we are all members of one human family.”

The U.S. women’s basketball coach, Geno Auriemma, called the Olympics “a two-week haven where people can get away from it all.”

“Every time you get here, get settled in, nothing seems to matter to any country other than the competition — as it should be,” said Auriemma, now at his third games. “These two weeks, the joy and spirit of competition seems to win out.”

And even on the streets of Rio, some Brazilians are beginning to embrace the moment and all that it means.

“Finally people are beginning to feel the Olympic spirit,” said Ilene Pessoa, a college administrator who lives in Rio’s Copacabana neighborhood. “The eyes of the world are on us.”