The thing I find scary is most teams/ nations have their hooligans. The "fans" that let their team down by thinking fighting makes them a real man. But then with the Russian hooligans we have seen in France it is different.. They seem like they are militarised, some have been reported wearing armour and carrying guns. Some have even been rumoured to use tactics to splitten people from groups etc. Now that is scary shit.
The Russian hooligan problem is huge. I was chased in St.Petersburg when I just had a drink with 3 friends. Not wearing any gear, they just knew we talked in German.
I have no clue how they want to protect visiting fans in 2018.
Even fucking Poland who had a huge problem in the early 2000's got their shit together(relatively speaking) by legislations and hiring social workers who take care of violent fans.(They basically implemented Germany's system which was a success). You have to tackle those issues long before the event but Russia has done fuck all.
Throwing more police at violent thugs will just cause more riots.
Russian ultras are more like hardcore organised gangs at times. Your average English diehard hooligan would shit himself. These guys don't fuck around.
The diehard English hooligan scene is dead for almost 15 years now.