At 10 p.m. on Wednesday, 19 February, 43-year-old Tobias Rathjen opened fire in a shisha bar in the western German town of Hanau, 15 miles from Frankfurt. Having killed four people he moved on to another shisha bar, sprayed bullets into the crowd and killed five more people. He returned home in his black BMW, shot his mother and then turned the gun, a pistol he had acquired legally and used regularly at a local shooting club, on himself.

By the time I started reading the rolling newsfeeds the next morning, it had been established that the murders were an act of terrorism. For all the madness in the rambling manifesto he had published on his website a few days earlier, Rathjen held a consistent white-supremacist worldview. Apart from his mother, his victims were of non-German – Turkish, Afghan, Romanian, Bulgarian, Bosnian – origin. Later on Thursday, Angela Merkel made a clear statement: ‘Racism is poison. Hate is poison. And this poison exists in our society.’

One of my colleagues grew up in Hanau. His parents owned a greengrocers round the corner from one of the bars. ‘I am utterly bewildered,’ he told me on Friday, ‘that this could happen in the Hanau I know from childhood where most people simply want to bring up their children in a safe environment.’

Right-wing extremism in Germany is a real and growing threat. Between 2000 and 2011, a group calling itself the National Socialist Underground committed a series of murders; for years the German security forces failed to identify the crimes as the work of right-wing extremists. In Munich in July 2016, an 18-year-old schoolboy shot nine people in a racially motivated attack and then killed himself. Walter Lübcke, a CDU politician who had vocally supported Angela Merkel’s refugee policy, was assassinated by a neo-Nazi in June 2019. In Halle last October, a botched attack on a synagogue was followed by the shooting of two people, one outside the Jewish cemetery next to the synagogue, the other in a kebab shop. Last week’s attack in Hanau came just days after security forces exposed a terrorist cell (‘Gruppe S’) that had been planning to strike mosques across Germany.

There has also been an increase in smaller, everyday racist attacks, from graffiti to arson. Pegida (Patriotic Europeans Against the Islamisation of the West) held its 200th march in Dresden on 17 February. The far-right AfD (Alternative für Deutschland) won 12.6 per cent of the national vote in the 2017 Bundestag elections. In 2018, Alexander Gauland, the then co-leader of the AfD, referred to Hitler and National Socialism as ‘chicken shit’ in the longer course of German history (for which he was deeply criticised outside his party). ‘How lacking in consciousness must our society be not to see a connection?’ my colleague said.

A sense of the connection – direct or indirect – between AfD rhetoric and the terrorist attack in Hanau extends beyond the tens of thousands of ordinary Germans who have taken to the streets, forming human chains or holding candlelit vigils in market squares, or those observing a minute’s silence at the beginning of football matches and the Berlinale. In the media and in private conversation, there is a deep sense of responsibility. Right-wing conspiracy theories are propagated across global networks; but people falling for them and acting on them is seen as a homegrown problem requiring a homegrown solution. Whether or not Tobias Rathjen was in a state of psychosis last Wednesday night, he was a terrifying example of someone absorbing a well-developed ideology and taking it to its extreme, empowered by a sense that he was fighting for a cause with more and more support.

Twice a year, my family and I get off the train at Hanau when we visit my parents-in-law. We drive out of town past those ordinary houses in which most people just want to bring up their children safely. Now that I have German citizenship, I, too, am part of this, but the complexity of the challenge is overwhelming. Blaming the AfD is too easy. Its offensive rhetoric has legitimised extremist views, but banning the party wouldn’t make the ideology disappear. Stricter online policing might help catch the next Tobias Rathjen before he drives out armed on a dark night in another ordinary town. Tighter gun control might help too. But we will also have to ask painful questions. Where do such ideologies stem from, what is it about contemporary German society that feeds them, and how can we prevent people from being seduced by them?

On YouTube, I watched Andreas Schmitt’s carnival speech in Mainz, which is traditionally meant to make everyone laugh. Not this year. ‘The murders in Hanau, the shooting at the synagogue in Halle: whether Jew, Christian or Muslim, that was an attack on us all. We live here together, democracy will triumph and you’ – right-wing extremists – ‘will never govern our country.’ To start speaking out against acts of everyday racism is the least we can do.