Soccer supporters as a whole have to be the most passionate of any group of sports fans in the world.

Where soccer rules, all else is almost forgotten. Most soccer supporters in other countries aren’t sports fans, they’re soccer fans, and the passion is clearly visible when soccer is on its greatest stage.

Remember the “we’ll sing ’til the final whistle blows” South Korean fans at the 2002 World Cup? They were an entertaining group.

However, when passion turns to anger, soccer stadiums become battlegrounds, where hooligans turn peaceful matches into life-threatening situations.

In the last month, European soccer has experienced a rebirth of hooliganism, and the timing couldn’t be any worse with the 2006 World Cup set to play out in Germany – one of the countries at the heart of this new-wave hooliganism. If the ruling bodies like FIFA can’t curb the hooliganism, there’s no telling what could happen in Germany a year from now.

If you saw what happened during the Inter Milan/AC Milan UEFA Champions League match on Tuesday, you know how bad hooliganism can get. Late in the second half, with AC Milan leading 3-0 on aggregate, Inter scored, but the goal was disallowed by referee Markus Merk. Merk ruled that AC’s keeper, Dida, had been fouled on the play.

Cue the frustrated Inter fans. For the next 15 minutes, they covered the field in lit signal flares, turning the pitch into something that looked more like a set for Spielberg’s next big war epic than a soccer field. One of the flares struck Dida square in the back of the neck; he is questionable for AC’s continuance in the Champions League.

The Inter/AC incident was one of many.

On Sunday, 17 fans were arrested during Italian league matches after clashing with police. The racist, fascist, neo-Nazi garb and banners showcased by these fans were said to have started quarrels in the stands.

On Wednesday, two police vehicles and another car were torched by fans outside the Champions League match between Juventus and Liverpool, an incident that no doubt stemmed from the previous bad blood between the fans of the two sides. Thirty-nine people were left dead following riots between Juventus and Liverpool fans at the 1985 European Cup Final.

Two weeks ago, during a friendly match between Germany and Slovenia, riots broke out in the stands, and police arrested 65 fans.

Two days later, German fans followed suit at several second division matches in the cities of Aue, Essen and Aachen. During a match between Energie Cottbus and Aue, Energie head coach Petrik Sander was left unconscious and hospitalized after a mini-bomb went off only a few yards from where Sander was standing on the sideline.

Hundreds of fans fought with police in all three cities. Stadiums and surrounding parks were vandalized. Two police officers and dozens of civilians were seriously injured. Police arrested 25 people; hundreds more should have shared the same fate.

European fans have also become notorious recently for throwing bananas at black players during matches, including Thierry Henry, widely considered by many as the best player in the world.

Italian soccer officials have acted quickly. Effective Thursday morning, any match halted by fan behavior immediately becomes a 3-0 win for the opposing side. They have also threatened to make teams with misbehaving fans play in empty stadiums.

It’s a good start, but it’s not enough. How is it that fans can smuggle in dozens of flares? You would think if these fans can get flares in the stadiums, they would almost certainly be able to get guns inside – worse yet, larger, more potent bombs than the one that injured Sander.

Where’s the security? We’re not talking about a flare here and there, we’re talking about dozens. That’s not good enough. If this keeps up, we’re going to see 1985 Juventus/Liverpool all over again real soon. The world’s game doesn’t need that right now.

With the World Cup in Germany fast-approaching, this renaissance in European hooliganism creates troubling visions into the future, when the most passionate fans in the world will gather to support their teams’ bids for soccer’s ultimate prize.

Those flares in Milan, every one of them, sent an alarming signal to the soccer world: unruly fans have to be stopped, or they’ll keep it up all the way to Germany.