Wilmots' club is the next obstacle blocking the United States' path, with the teams squaring off at Arena Fonte Nova on Tuesday in the round of 16.
Back home, however, the small European nation is in the midst of intense debate about its very future, with a separatist movement gaining strength. And Wilmots bristles uncomfortably when the topic creeps into his World Cup press conferences.
"I don't understand, is there a war in Belgium?" he snapped Monday. "I don't see where the problem is."
To clarify, Belgium is politically locked in a standoff with no major party able to form a government and an age-old split between two distinct regions, with different languages, flaring up again. Belgium comprises Flemish-speaking Flanders and French-speaking Wallonia, and political differences have been a theme for generations, coming to a head recently amid calls for Flemish independence.
There is little ideological agreement and there have even been suggestions that the nation of Belgium could cease to exist if the regions separate, a possibility put forward by a Flemish politician. The only common ground seems to come with soccer, with the citizens coming together in support of Wilmots and his players.
[Related: Why U.S. absolutely cannot lose to Belgium]
"When the national team plays everyone gets behind them, everyone supports them," journalist Robby Morren of Voetbalkrant.com told Yahoo Sports. "No one is thinking about politics when the team is playing. Everyone is together and united."
That philosophy has been borne out here in Brazil, where Belgian fans from both sectors of the country have found kinship through soccer.
"Sadly, I have to admit there will still be differences when we get back home," said Pieter Goor, a Flemish-speaking Belgian fan who flew into Salvador on Monday morning. "We want different things. Here we want the same thing. We want to win the Cup."
Goor was standing near a new friend, Cyrille Mahy, a French-speaker from the Wallonian city of Charleroi. The pair met and became pals on this trip, when Mahy bought a spare match ticket from Goor.
"We don't talk politics here," Mahy said. "We don't talk about Di Rupo and the N-VA. We talk about Eden Hazard and Jan Vertonghen." To explain, Elio Di Rupo is Belgium's prime minister, while the N-VA refers to the Nieuw-Vlaamse Alliantie (New Flemish Alliance), which would like a peaceful and gradual secession of Flanders from Belgium.
Hazard and Vertonghen are players who represent the mixed face of the national team. Chelsea star Hazard is a Francophone from Wallonia; Vertonghen, of Tottenham in the English Premier League, a Flemish speaker from Flanders.
As a French speaker who married a Flemish woman and a former senator at that, Wilmots is about as Belgian as it gets, and his team has become a strong symbol for togetherness.
Captain Vincent Kompany, an injury doubt for the game with the U.S., voiced hope that the team can stand for unity. "Proud of my team, proud of our country, together we can achieve anything," he tweeted.
Belgium will rely on the traveling version of that support here on Tuesday, with the crowd expected to have a heavy U.S. presence in Salvador.
[Related: How Team Belgium overcame love triangle]
Wilmots is in charge of an outstanding team that cruised through European World Cup qualifying and has electrified the country with its flowing style. He admitted the tournament would be considered a failure if his squad was unable to move past the U.S.
However, he has respect for the way Jurgen Klinsmann's American squad moved through the Group of Death to set up this clash and the two coaches are on friendly terms, even setting up a behind-closed-doors scrimmage before the tournament that was ultimately cancelled due to traffic concerns.
Things get a bit more hostile now though, with everything to play for and survival or elimination on the line. Personal pride and national pride are at stake with Belgian's temporarily united citizens hoping of a nation on their side.
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