When France plays Morocco on Thursday in Boston, it will be the next chapter in what has become a dramatic subplot of these World Cup tournaments: a postcolonial clash, laden with history, symbolism and a dash of score settling.

The two countries are intertwined by colonial dominion — Morocco was a protectorate of France from 1912 to 1956 — and then by waves of emigration across the Mediterranean Sea in the 1960s and 1970s. About 1.5 million people of Moroccan descent, most Muslim, now live in France. Many have thrived, but others have struggled to carve out an identity amid questioning of their Frenchness by the far right and other nationalists. All of that sharpens a soccer rivalry as fierce as any in the world.

Morocco’s team, undefeated in 34 games, will be hungry to avenge its 2-0 loss in the World Cup semifinals in 2022 to France, which is the favorite to win this year’s tournament. Clashes after that game led to scores of arrests in Paris, and the authorities are girding for more unrest, regardless of who wins on Thursday. France’s interior minister, Laurent Nuñez, said security in the capital would be reinforced.

Excitement over the rematch between the Atlas Lions of Morocco and Les Bleus of France, as the teams are known, is sky-high. Moroccan and French flags ripple from cars and drape from windows across Paris. Starting on Thursday, the city said, it will allow restaurants and bars to keep outdoor terraces open until 2 a.m. to accommodate crowds watching World Cup games.

For some French Moroccans, there is a double sense of pride at the success of their two homelands, said Yassine El Yattioui, a French Moroccan professor of international relations at the University of Salamanca in Spain.

“Franco-Moroccans,” the professor said, “say to themselves, ‘Look at our homeland, France — it’s a great soccer nation, a country that keeps winning titles and putting on great tournaments,’ whereas now Morocco is the underdog that has become a powerhouse.”

What makes this game striking, sports historians and analysts said, is the parallels between the French and Moroccan teams. Six members of Morocco’s squad were born in France. In an era in which soccer players often play for countries where they were not born, that is not unusual. But it illustrates the depth and complexity of the ties between France and its former protectorate.

“There’s a way in which this game is France versus France,” said Laurent Dubois, a professor of history at the University of Virginia and the author of “Soccer Empire: The World Cup and the Future of France.” “So many of the Moroccan team members grew up in France, on the outskirts of Paris.”

Morocco’s squad also includes six players from Spain, three each from the Netherlands and Belgium, and one from Canada. Just six of the squad were born in Morocco, which attests to the talent that diaspora populations can bring to African teams.

For those dual nationals who choose to play for Morocco rather than for European countries, the decision can be pragmatic rather than emotional, rooted in the calculation that it might be easier to make the team and get playing time.

“The most important thing was that they made strategic choices,” said Stéphane Beaud, a sociologist who just published a book on the French soccer star Zinedine Zidane, though he noted that “Morocco has become a very good national team over the last 10 years,” closing the gap with Europe.

The French team, too, reflects the web of ties between France and Africa. Three of its players were born abroad, including its star winger, Michael Olise, who was born in Britain to parents with roots in Algeria, France and Nigeria. Many others are from French immigrant families, with roots in African countries like Algeria, Cameroon, Mali, Senegal — though none of the current players identify as Moroccan.

The diverse origins of France’s team once made it a target for racial gibes on the far right. In 1996, the founder of the far-right party the National Front, Jean-Marie Le Pen, questioned the team’s French identity, saying it was “artificial to bring in players from abroad and call them the French national team.” All but one member of that team had been born in France.

Yet in this tournament, the most eye-catching phenomenon is the number of players France has supplied to World Cup teams: 99 in all, according to Transfermarkt, a German website that collects statistics on soccer. A majority were born in Paris, making it the sport’s undisputed training ground.

The prolific success of French soccer — Les Bleus have won two World Cup titles in the last 28 years — has made it harder to target the team, according to Professor Dubois. Marine Le Pen, a daughter of Mr. Le Pen and a far-right candidate for president, tangled recently with its captain and star striker, Kylian Mbappé, after he warned of the dangers should the far right take control of France.

Ms. Le Pen, who has labored to remove the taint of racism from her party, kept the back and forth with him on the level of locker-room taunts. Rather than question his Frenchness, she noted on social media that Mr. Mbappé had left his club team, Paris St.-Germain, for Real Madrid, only to watch his former team go on to win the Champions League.

Professor Dubois noted that racist remarks were now more likely to be flung at Black political figures, such as Bally Bagayoko, the mayor of St.-Denis, a northern suburb of Paris. Mr. Bagayoko, born in France to parents of Malian descent, has endured a stream of abuse since being elected in March.

“The far right has lost the cultural war against the French team,” Professor Dubois said. “It’s almost like the terrain has shifted.”

Still, France’s success on the field has not spared its team the occasional ugly outburst. After France defeated Paraguay in a hard-fought game last week, a member of Paraguay’s Senate, Celeste Amarilla, posted a racist rant against Mr. Mbappé, describing him as a “colonized Cameroonian, desperately trying to ⁠pass himself off as French.”

Mr. Mbappé replied that Ms. Amarilla was a “despicable woman” and “unworthy” of her position. He added, “You do not represent Paraguay, that country which has sweated passion and honor throughout the competition.”