- Soccer violence at Euro 2012 sparks fears for 2018 World Cup in Russia
- Russian fans fought with Polish supporters ahead of group match in Warsaw
- Experts say the violence could have been prevented with more forethought
- Polish authorities sanctioned a Russian national day march through the city
The scenes were shocking. Hooliganism is supposed to be a thing of the past, but the fighting in the streets of Warsaw during the opening week of Euro 2012 was a stark reminder that football's "disease" has not been cured.
The first major tournament to be held in Eastern Europe has already provided a cocktail of color and a wealth of excitement on the pitch, but the violence between Russia and Poland fans has cast a shadow over the continent's showcase event.
Despite being on a small scale so far, the problems have turned the spotlight towards 2018 -- when Russia will host the planet's biggest soccer spectacle, the World Cup.
"The Russian press are obviously very, very upset about what has happened," Russian football expert James Appell told CNN. "How this will affect attitudes towards 2018 won't come from inside Russia, it'll be a baton that is picked up by the international press and by UEFA and international footballing authorities.
"I think Russia will only react to criticism if it comes from outside. I don't think Russian authorities have really taken the kind of steps that have been needed through pressure on a domestic front.
"I'd expect in the aftermath of what has happened that the European footballing authorities and perhaps even FIFA will step in and mandate some kind of changes that need to be made in Russian football in order for 2018 to go ahead peacefully."
Geoff Pearson, an expert on football hooliganism at England's University of Liverpool, believes Russian authorities need to take an initiative ahead of the World Cup.
"They need to be able to identify who these groups are in each city because it is almost certain these groups will look to attack certain groups of fans that travel to Russia for the World Cup in the same way the Polish hooligan groups have attacked Russian fans in Warsaw," Pearson told CNN.
"The important thing is that the police, between now and 2018, are able to identify who these groups are and that they are closely monitored so they don't cause trouble."
Trouble also erupted at Russia's first match as the tournament kicked off last Friday, when a black Czech Republic player was allegedly subject to racist chants and four Polish stewards attacked in the stands.
It is not the first time violence has tainted the European Championship. In 1980, when Italy hosted the tournament, England's clash with Belgium had to be halted due to fighting in the stands. In 1988, police arrested English, Dutch and German fans due to violence.
And at Euro 2000, nearly 1,000 England fans were arrested after riots in the Belgian cities of Charleroi and Brussels.
European soccer's ruling body UEFA has often been accused of failing to properly punish such problems, but this week it fined the Russian Football Union $149,000 and threatened its national team with a six-point deduction for the Euro 2016 qualifiers if there is any repeat.
It may act again over Tuesday's street brawls, where police arrested 184 people -- 157 Polish and 24 Russian -- after a Russian national day march through Poland's capital sparked confrontations.
Appell believes Friday's events should have proved a forewarning.
"The violence was 100% predictable," he said. "You can talk about the immediate short-term context, which was thousands of Russian fans coming over to Poland and causing trouble in the stadium in Wroclaw on Friday in the match with the Czech Republic.