What led medicine student along path towards terrorism?

IS is a gang. The biggest there is, but a gang nonetheless.

Remembering that the men behind the west London terror plot were gangsters as well as terrorists might make it easier to explain what motivated them.

It’s time to ask the familiar ‘why?’ question that always follows a terrorist conviction.

Sensible explanations of what drives British youngsters to Islamist extremism tend to consider the impact of UK military action in Iraq and Afghanistan - and inaction in Syria.

But many terrorists, including Tarik Hassane, are also influenced by some of the same factors that entice people into street gangs: boredom, frustration, identity, protection, the appeal of what’s considered ‘macho’.

There is a significant overlap between criminal gangs and terrorist groups, and perhaps this case illustrates that more than any other in Britain.

Hassane is a well-educated son of a diplomat - not the usual background for a gangster. But he took the same journey made by dozens of west London youngsters, from schoolboy to extremist.

He came from one of a few neighbourhoods in the area which have become breeding grounds for IS. Their cases reveal that for all the talk of online recruitment, radicalisation is often a face-to-face, out-in-the-open business carried out within friendship groups.

In an online message posted by Hassane a few months before his arrest and seen by ITV News, he said he “became religious” as a teenager after he “met some good older practicing brothers. Started hanging around with them…”

Hassane had been influenced by friends and associates. They included Mohammed Emwazi, the IS executioner known as ‘Jihadi John’, who was beginning his killing spree in Syria as Hassane drew up his plot. Alexe Kotey, whose influence on Emwazi was revealed by ITV News last month, was a lynchpin in the west London network. Together they drew each other towards terrorism.

Shortly after Kotey and Emwazi left for Syria, Hassane moved to Sudan to study medicine. He told his friends there that he was going home for a week to see his parents. Shortly after arriving in London, he was arrested.

He had shown bravado to his gang mates, but none of it to his classmates. He concealed his plot and his politics from them.

“He left all his stuff behind in Sudan so everyone expected him to come back” said one friend who studied with him in Khartoum, and spoke to him days before his departure.

“He never said Britain was the enemy. He always tried to go back regularly. He was a fun guy who loved Playstation and football. He’d always say that he wanted to be a footballer rather than a surgeon - not a terrorist.”

But when he left Khartoum for London, he had already become the first Islamist terrorist in Britain to obtain a working firearm for his plot.

Just like the Paris attackers, he was a young man who had been influenced by extremist gangs, and who tried to use gangland methods to carry out an atrocity.