Four youths beat a man to within an inch of his life in Berlin and the police examine surveillance video in a U-Bahn metro station to identify them. A few days later, cameras at another station capture images of thugs beating up a homeless man.

Similar images have been collected in Munich and other cities across Germany. These grainy videos document the violent excesses of everyday life on our public transportation.

We only ever see them when the brutality recorded is so excessive and unusual that the victim’s testimony does not lead to the capture of the criminals.

But the underground recordings imply something else too: that the dangers you face on a U-Bahn train at night are not so insignificant anymore. Defenders of public transport will of course argue that of the hundreds of thousands of kilometres travelled by hundreds of thousands of passengers, there are very few acts of violence. And they’re right, but they’re missing the problem.

Public transportation has more to lose than its reputation. You can suppress the feeling that you no longer feel safe after hours at a metro station, but in Berlin it’s hard to escape the impression that the city’s public infrastructure is being allowed to fall into zones of lawlessness.

The German capital’s police chief might point to figures that show that the number of violent crimes solved in Berlin is only slightly below that of wealthier Hamburg. He might also talk about the city’s successful handling of repeat youth offenders.

That might all be true enough, but the slogan “We will get you!” is no more effective than the presence of CCTV cameras in stations – they won’t deter a thug from committing violence.

No-one really believes that the demand for “another thousand policemen” – which we will hear from our politicians often enough in this election year – can stop the decline of public spaces. But the old “broken windows theory” – which says acceptance of decay, vandalism and misdemeanours automatically leads to more serious crimes – didn’t apply only to New York in its own “poor-but-sexy” days decades ago. It applies just as well to Berlin now.

It’s become normal for the Berlin city government to ignore everything that most law-abiding citizens consider a problem. The police budget has been cut to the point where it has become impossible for officers to react to low-level infractions. And so the city’s public transportation has been abandoned to lawless thugs.

This commentary was published with the kind permission of Berlin newspaper Der Tagesspiegel, where it originally appeared in German. Translation by The Local.