There are both similarities and differences between the two incidents. The articles cited by the two posts from the Financial Times and New York Times, respectively, reserve their criticism for the United States and our allies. According to that story the rise of DAESH was caused by our “blundering about” the Middle East and the murders in Christchurch provoked by “white supremacy”. IMO there’s more truth in the latter account than in the former but that, too, is an insufficient explanation.
The murders in New Zealand tell a story of personal superempowerment. A single individual or a small number of individuals are able to wield enormous power. Laws that would actually make such a thing impossible would also make modern life impossible. Banning guns would not be enough. You’d need to ban the materials necessary to make explosives, chemical weapons, or bacteriological weapons as well.
This will only get worse. Where an individual or handful of people today can kill dozens, tomorrow they will be able to kill hundreds, thousands, or even hundreds of thousands.
The rise of DAESH on the other hand was the result of a concerted effort by first dozens, then hundreds, then thousands, then tens of thousands of like-minded people over a decade. That effort was facilitated by social media. Radical Islamist groups aren’t new in Islam—they are as old as Islam—but being able to organize them over vast distances in a relatively short timeframe is new. Our “blundering about” is an aggravating factor rather than a cause.
As a society we have decided that our response to personal superempowerment will be to tolerate it—just to accept that every so often there will be a mass murder. We may make the same decision about radical Islamist groups but the comparison is a stretch.