Kettled into a corner, the England fans are singing. Some of it is stupid stuff, some of it profane.
There is plenty of booze going down, and all it takes is for one shove at a baton-wielding officer, or one idiot to dispose of a bottle over the line of riot shields, for it all to go off.
And if the setting for this scene is France, then then the way the police carry themselves will always ensure that it does go off.
As a journalist, I've covered football matches in 25 different countries – mostly with Chelsea, one or two with England.
I'm not one for sitting in chain hotels, watching CNN, and ordering from room service: I go out, see the town, spend some time taking in the fan experience.
As well as seeing what goes on first hand, I also get reports from those who stand in the away end, while I file copy from the press tribune.
And, without any shadow of a doubt, no country among those 25 polices football more aggressively, in a way more likely to provoke exactly the sort of scenes we are seeing right now, than France.
I will not defend those fans, English or otherwise, who have gone to France simply to make trouble.
Just as I won't defend those who go with innocent intentions and get whooped-up into some violent state by a heady mix of lager and nationalism.
But, frankly, the scenes we are seeing involving England fans in France are, for the most part, very similar to those that play out on any English high street, on any Friday or Saturday night.
The English drink too much, can't handle their ale, and are prone to kicking off at authority when these things are pointed out to them.
It is a cultural thing: maybe some psychologist somewhere can blame it on the trauma of losing an Empire.
I prefer to think it is to do with a licensing regime that has, over the last 20 years, swerved from pubs being family owned and run, keeping strong relationships with their customers, and well-defined opening hours; to chain booze supermarkets where the only imperative is to sell more, for longer.
The French know all of this. They hold well-formed national stereotypes of us English that play upon it.
And, going into a tournament football situation, any responsible authority would expect to take it into account.
Of those 25 countries in which I have experienced football, the best at policing matchday situations, by far, is Germany.
There the police understand cultural factors such as this, and put them to play.
That hasn't always been the case: certainly, some will recall Chelsea's game against Besiktas in Gelsenkirchen back in 2003, where officers appeared untrained and clueless.
But since the decision was made to award the Germans the 2006 World Cup, they have significantly upped their game.
Whereas in France, officers will corral visiting fans into a tight spot, before bashing them wish shields and tear gassing them (see: Paris Saint-Germain v Chelsea in 2015, among others), the Germans employ community policing.
They mingle with crowds, sharing jokes, but always making sure fans know who is in charge.
The German police almost all seem to speak English, and are happy to do so; while their French colleagues either do not, or refuse to bother.
Yes, it is a national disgrace that our education system turns out people who expect to go anywhere in the world and bark loudly in English to be understood; but a crowd disorder situation is not the time to chuck out copies of Tricolore, and ask people to conjugate their verbs.
The Germans dress low-key, the French as Robocop.
All of this creates a situation where fans in France are drunk and on-edge, when they should be simply drunk.
Even in England, where the policing of matches varies wildly from force to force (West Midlands Police may be the pettiest force on these shores in a footballing situation), these lessons have largely been learned.
Body armour is worn beneath uniforms, not on top, so – unlike the Compagnies Républicaines de Sécurité (CRS) in France – fans are not immediately plunged into a conflict situation.
Stopping, for a moment, to be fair to the CRS: these are incredibly difficult times for them.
These are the same officers who are charged with responding to the horrific tide of terrorism that has hit France in recent years.
But, while they can be forgiven for being on-edge, it is simply nonsensical to attempt to police a football match as if it were a terrorist outrage.
For these reasons, and many more, trouble at Euro 2016 was inevitable almost from the moment it was awarded to France.
There are lessons for all parties to learn here, though it doesn't seem many have the time or the inclination to do that at this stage of proceedings.
But, for England's travelling fans, there is one important thing to consider: the next World Cup is in Russia; and the Politsiya really aren't to be messed with.