No surprise that London attacker was born in UK | Jason Burke

The news that the London attacker was born in Britain and inspired by extremist Islamist ideology was entirely predictable, as was his criminal record.

The standout detail from the sketchy profile we have of Khalid Masood is his age: 52, nearly twice that of most contemporary attackers.

The attack was claimed on Thursday by Islamic State. The group has been selective with such statements, which are credible, and careful in its vocabulary.

Significantly, Isis described a “soldier” who responded to its “call”, indicating the group probably did not have prior contact with Masood before the killings.

The same terminology has been used to describe people such as Omar Mateen, who opened fire in a nightclub in Florida in June and claimed allegiance to Isis during the attack, and Mohamed Lahouaiej-Bouhlel, who drove a truck into a parade in Nice in July.

Other words tend to be used to describe attackers like those who made up the network responsible for attacks in Paris and Brussels last year. They, for the most part, were trained, commissioned and dispatched by Isis planners after spending time in Syria.

One aim of Isis is to give the impression of global reach. The statement of responsibility for the London attack was issued in Arabic, French and German as well as English. There are many reasons for this.

One is that the group needs to boost the flagging morale of its recruits and sympathisers in the Middle East and Europe, which has been sapped by months of military reverses. The Isis motto is: “To endure and expand”. It has done little of either recently.

Isis has always used violence to achieve three main aims: terrorise (inspire irrational fear in a target population, usually civilian), polarise (communities to create recruits through greater tensions) and mobilise its followers.

A second reason is that the roots of jihadist ideology lie in the idea that every member of the global Muslim community – the ummah – has an individual obligation to act in defence of any co-religionists anywhere if they are under attack, without asking for permission from a ruler, parent or elder. This means that every extremist organisation has at the very least to acknowledge the ideal of a unified worldwide struggle.

A third is that recruitment to such groups, especially Isis, depends in part on the idea that volunteers are committing themselves to something that has a relevance and presence everywhere.

Finally, the nature of terrorist trends gives a false impression. On Thursday a man was arrested for trying to drive a car into a crowd in Antwerp. He had a shotgun and bladed weapons. Tactics spread quickly across international frontiers. A global plot? Or simply the copycat effect? The latter is almost certainly the case.

The reality is that contemporary Islamic extremist violence has never been as international as often imagined by the terrorists or their victims. The 11 September 2001 attacks involved hijackers who flew thousands of miles from homes in the Middle East and lived in the US for months before striking. But this was an anomaly, though one that distorted thinking about the nature of the threat for a decade.

A vast proportion of attacks over the 16 years since have involved local volunteers attacking local targets. This is true of the conflicts in the Islamic world, where most terrorist casualties are inflicted. In 2010 intelligence officials in Afghanistan were surprised to learn that most Taliban attackers operated within 15 miles of home. The ranks of Boko Haram in Nigeria and al-Shabaab in Somalia are full of Nigerians and Somalis, not foreigners. It is true too in the west.

In Spain, the Madrid bombings of 2004 were the work of a network of people who lived less than a mile from the station where they killed nearly 200 people. The London bombers of 7 July 2005 were from northern England and the city’s extended suburbs. The killers of off-duty soldier Lee Rigby in south-east London in 2013 lived a short drive from the site of the murder. The brothers who attacked the offices of the satirical magazine Charlie Hebdo in Paris in January 2015 lived a short drive from their target, while most of the network that attacked the city 11 months later were French, or Francophone Belgian. The Nice attacker was a long-term resident of the port city.

There are exceptions. The Berlin attack before Christmas involved a transient Tunisian. A handful of the Paris attackers were from the Middle East.

Many of these men had previous involvement in serious and petty crime. For those already living on the margins of society and the law, the step towards violent activism is smaller than it might otherwise be. Prison is a key site of exposure to radical ideologies and people. Criminal contacts can provide essential – if often inadvertent – logistical help.

The significance of Masood’s age will later become clear. For the moment it simply underlines the variety of extremist profiles, and the unpredictability of the threat. Most Islamic militants have been between the ages of 18 and 35, with the average age declining in recent years. Some analysts see their attraction to radicalism as partly a generational rebellion. Violent rightwing militants tend to be much older. Thomas Mair, who killed MP Jo Cox last year, was 52.

Every case is, of course, unique. And the reality is that, much as all politics is essentially local, so is terrorism. Islamic extremist strategists have wrestled with this challenge to their global vision for years, and have yet to evolve an adequate response. Western experts argue interminably over whether the motives of individuals are 10% ideology and 90% local context or vice versa.

But the sad reality is that, though it may be reassuring to blame bad guys, or bad ideas, from a long way away for violence at home, no one should be surprised that the man who attacked one of Britain’s most symbolically charged locations was born in the UK.