“Hate is a poison that… is responsible for far too many crimes,” said the German chancellor, Angela Merkel, after the killing of nine people in a far-right terror attack on two shisha bars in the German town of Hanau last week. “This is neither rightwing nor leftwing terror, it’s the crazy act of a deranged man,” responded Jörg Meuthen, a spokesman for the virulently anti-immigrant Alternative für Deutschland (AfD).

It’s an argument that’s becoming as depressingly familiar as the attacks themselves. The Hanau killings follow the murder last June of the Christian Democrat politician and champion of refugee rights Walter Lübcke and an attempt in October to storm a synagogue in the eastern city of Halle. Days before the attack, German police made raids across the country to take down a terror cell allegedly planning to plunge Germany into a “state of civil war” by attacking Muslims and asylum-seekers.

It’s not as endemic as Islamic jihadism but white nationalist violence is becoming a major issue

These incidents have raised again questions about the nature of German politics and culture. This is not, however, simply a German disease. From Anders Breivik at Utøya to Dylann Roof, who killed nine black people at a Charleston church, from Thomas Mair, who murdered the MP Jo Cox to Brenton Tarrant, currently awaiting trial for the Christchurch mosque shootings, far-right terror is a global problem. It’s not as endemic as Islamic jihadism but, especially in Europe and America, white nationalist violence is becoming a major issue.

Far-right terrorism does not exist in isolation, any more than jihadism does. As with jihadism, personal and political grievances become refracted through the politics of identity to create a worldview shaped by a noxious brew of visceral racism and conspiracy fantasies. The individuals involved may be delusional, but those delusions feed upon sentiments nurtured by our political culture. It’s not a general problem of “hatred” but the specific vilification of migrants and Muslims and the encouragement of ideas of white victimhood.

“Europe is committing suicide. Or at least its leaders have decided to commit suicide… by the end of the lifespans of most people currently alive, Europe will not be Europe and the peoples of Europe will have lost the only place in the world we had to call home.” Apart from in the elegance of expression, that thought, and that sentence, would not have been out of place in the manifesto of the Hanau gunman Tobias Rathjen. In fact, it appears on the opening page of Douglas Murray’s 2017 bestseller The Strange Death of Europe. The American writer Christopher Caldwell argued in his acclaimed Reflections on the Revolution in Europe that immigration to Europe has been akin to “colonisation”. Another prominent American writer, Sam Harris, has claimed that “the people who speak most sensibly about the threat that Islam poses to Europe are actually fascists”.

Ideas that once were confined to the fringes are now routinely and unashamedly aired by mainstream commentators. We are constantly told that unless we normalise “white racial self-identity” and address the “cultural anxiety” that immigration creates by more tightly controlling immigration, then the far right will prosper. In reality, the opposite is true: the more we give credence to ideas that once belonged only to the fringe, the more that fringe will become legitimate.

The politics of identity is at root the politics of the reactionary right

Migrants are now held responsible not just for the ills of society but even for their own murder. Rachida Dati, the centre-right candidate to be mayor of Paris, suggested that the blame for the Hanau killings lay with Merkel’s too-liberal immigration policies.

If the right’s obsession with immigration has helped give new legitimacy to arguments of the far right, so has the left’s blindness to the consequences of the politics of identity. Many on the left now embrace the idea that one’s interests and values are defined primarily by one’s ethnic or cultural or gender identity.

The politics of identity is, however, at root the politics of the reactionary right. The original politics of identity was that of racial difference, the insistence that one’s racial identity determines one’s moral and social place in the world. Now, identitarians of the far right are seizing upon the opportunity provided by the left’s adoption of identity politics to legitimise their once-toxic brand. Racism became rebranded as white identity politics.

It’s an expression of the pernicious befuddlement of today’s politics that rightwing critics of identity politics are among the most vehement defenders of the idea of a European homeland to be protected against immigrant invaders, while leftwing critics of white identity are staunch defenders of every other form of identity politics.

No one is responsible for an act of terror but the terrorists themselves. What the rest of us should not do, however, is provide legitimacy to their arguments or nurture their toxic beliefs.

• Kenan Malik is an Observer columnist