Twenty-four years after their first World Cup meeting billed as the "Mother of all football matches", Iran and the United States face off in a politically-charged showdown on Tuesday with a place in the knockout rounds up for grabs.
Decades of mutual enmity between the arch geopolitical foes is the backdrop to what promises to be a white-hot sporting occasion at Doha's Al Thumama Stadium.
In the context of the tournament, the stakes are simple -- a win for either team secures a place in the last 16 while defeat will guarantee elimination.
But the wider significance of the Group B contest is less clear-cut.
The United States and Iran have been bitter ideological enemies for more than four decades, severing diplomatic relations after the 1979 Islamic Revolution.
Quite what bearing that has on a 90-minute World Cup football match involving 22 players remains to be seen.
United States coach Gregg Berhalter has been at pains to dampen down suggestions that the game carries a political dimension.
"I envision the game being hotly contested for the fact that both teams want to advance to the next round -- not because of politics or because of relations between our countries," Berhalter said.
"We're soccer players and we're going to compete and they're going to compete and that's it."
Yet Berhalter's desire for politics to be absent from the occasion may be wishful thinking.
A rare public relations gaffe by US Soccer -- posting a modified version of Iran's national flag on the US team's social media feeds in what it said was a gesture of solidarity with Iranian women protesters -- has infuriated football authorities in Tehran.
The offending post was removed from official US Soccer feeds on Sunday after the Iran Football Federation lodged a complaint with world governing body FIFA.
The controversy almost certainly guarantees that what was already shaping as a nail-biting showdown on Tuesday is likely to carry a crackle of political tension.
- Handshakes and roses -
That was certainly the case when Iran and the USA met for the first time at the 1998 World Cup in France, the Iranians claiming a memorable 2-1 victory at the Stade Gerland in Lyon.
Political intrigue seeped into the build-up to the match with a row over the pre-game rituals.
Iran, the designated away team, refused to abide by the standard FIFA protocol of walking over to the American players for the handshake before kick-off.
That potential flashpoint was deftly defused by Swiss referee Urs Meier, who suggested that the two teams pose for a joint team photo.
Iran's players, who presented US players with bouquets of white roses to symbolise peace, happily complied, linking arms with their American counterparts.
Iran coach Jalal Talebi and veteran defender Mohammad Khakpour would later reveal how much the Iranians had invested emotionally in the game, viewed in some quarters as a battle against representatives of the "Great Satan."
"Just imagine being told for six months, repeatedly, that this game is the most important game in our history, which it really was," Talebi said in a 2018 interview.
Khakpour added: "I personally was contacted by people whose family members had been martyred, those who had lost children in the Iran-Iraq war. Fathers, mothers, called and said 'This game really does matter to us. You have to go and win this game for us.'"
The USA's coach at the 1998 World Cup, Steve Sampson, has since expressed regret that he did not use the political tensions between the two countries as a motivator.
"We were asked by FIFA, by US Soccer, by the organising committee in France, to make it about football, and not about politics. And I went along with that," Sampson told Time magazine.
"In hindsight, I would have made it about politics. A coach's job is to use any and every tool available to him to prepare his team."
Yet the American class of 2022 insist that politics won't come into the latest instalment of the US-Iran World Cup rivalry.
"The emotional side of having to win to get to the next round is enough to be up for it," US defender Tim Ream said on Sunday. "I don't think we have to worry about anything else.
"What is on the line is advancing into the knockout stages. And if that's not enough then I think we have issues."