“The differences between the two is now a matter of money,” said Lieven De Winter, a professor of contemporary politics at the Université catholique de Louvain. “Flanders is one of the most prosperous regions in Europe. Wallonia was, but it is now much weaker. It’s the classic discourse from Catalonia or northern Italy. Which region pays for social security?”

The situation has worsened in recent years, with the possibility that Belgium could split in two. When Flemish separatists won a significant share of the vote in the 2007 federal election, it sparked a political crisis that prevented a government being formed until 2011. The deadlock lasted for 541 days, breaking the world record for the longest period of time a country has operated without a government. The previous record was held by Iraq.

Until recently, Belgium’s soccer team had risen above the infighting. Despite being a tiny nation of 11 million (about the same as Ohio) it has a rich history in the game. It qualified for six consecutive World Cup finals and made a semifinal appearance at the 1986 tournament in Mexico, a moment heralded as a transformative for many Belgians.

“Since 1979 we’ve had a survey of how Belgian people feel,” De Winter said. “The Walloons have always felt Belgian, the Flemish hadn’t. That shifted in 1986 in the Flemish community: a jump in 15 percent from feeling Flemish to feeling Belgian. There was no other event in that period that might have triggered it.”

But Belgium has not qualified for a major tournament in a decade.

“When I was working in tennis, I never felt there was a problem at the player level because you speak the universal language of sport,” said Steven Martens, a former Davis Cup captain and the current general secretary of the Belgian soccer association. “But the language divide has been used on the national team level. When you have a Flemish coach, the French-speaking press is less indulgent with them and vice versa.”

Now that attitude has changed.

“We don’t see any signs of little clans appearing because it’s a well bonded, outspoken group,” he said of the current team. “They are symbolic for unity in the country.”