The faithful who gathered for Friday prayers at the Al Noor mosque in Christchurch, New Zealand, must have felt they were in the safest place in the world. Americans have become grimly familiar with gun violence and its awful aftermath. Many other countries – including France, Turkey, Tunisia and Germany – have suffered large-scale terrorist attacks and are in a near-constant state of alert. Elsewhere, individual atrocities – the 2004 Madrid train bombing or the Utoya attacks in Norway in 2011 – have left deep scars and forced people to factor additional risks into their daily lives.

New Zealand was largely insulated from such horrors – until yesterday, when at least 49 people were killed by a terrorist at the Al Noor mosque and at second mosque in the Christchurch suburb of Linwood. The gunman reportedly filmed himself as he entered the Al Noor mosque and began to fire indiscriminately, stopping only to re-load his weapon. Survivors afterwards spoke of the incessant sound of gunfire, and described the sight of bodies in pools of blood inside and outside the building. Australian prime minister Scott Morrisson described an Australian citizen arrested in connection with the attack as an “extremist right-wing” terrorist.

What prime minister Jacinda Ardern called New Zealand’s “darkest day” has left the country in shock and its small Muslim community in fear. The police investigation is at an early stage, but it’s clear the murders – the worst mass shooting in New Zealand’s history – will force us all to confront some difficult questions.

The authorities in New Zealand will have to review the country’s gun laws, which are lax compared to western standards (if not those of the US, which is an outlier). They must also establish how the killer was radicalised, and how the plot could have gone undetected. More broadly, however, the massacre underlines the very real dangers of a western public sphere in which Islamophobic hatred has, with the rise of the far-right, become increasingly not only tolerated but actively enabled and encouraged.