In recent months, discussions about the threat of terrorism, especially in Canada, focused on the solo work of amateurs egged on by Islamic State to take whatever lethal actions they could unleash, whether with a car or an old hunting rifle.
This week's Paris attack, however, reveals a less impulsive, more complex dynamic.
The attackers had ties to a previous pedigree of radicalism, to a wave of violence two decades ago when Algeria's civil war spilled over into France and powerful bombs killed and terrified Parisian commuters. Their affiliations diverged and mutated over time, as they sought an outlet for their radicalism and graduated from being part of a motley crew of neighbourhood wannabes to linking up with older generations of Islamic militants.
While Chérif Kouachi, one of the two brothers implicated in the attack on satirical magazine Charlie Hebdo, said they were sent by al-Qaeda's Yemeni branch, the third suspect, Amedy Coulibaly, said he was acting for Islamic State.
Nevertheless, they knew each other and Mr. Coulibaly said their actions were taken jointly.
In a telephone interview, Mr. Kouachi told BFMTV that he and his brother, Saïd, were financed by Anwar al-Awlaki, the American imam who moved to Yemen and recruited for al-Qaeda until he was killed in 2011 by a drone.
In a separate BFMTV interview, Mr. Coulibaly said he got his orders from the IS "caliphate." He said the three had agreed to co-ordinate their actions, striking at the same time. "We just synchronized the start. When they did Charlie Hebdo, I started doing the police."
As a result, while the Kouachis were on the run on Thursday, Mr. Coulibaly became the suspect in the fatal shooting of a female police officer and wounding of another person in the suburb of Montrouge. Their alleged actions mirrored the old al-Qaeda tactic of striking multiple targets at the same time.
The trio had known each other through their involvement in the Buttes-Chaumont cell, named after a Paris area where young petty criminals were radicalized a decade ago by a 26-year-old preacher named Farid Benyettou. Around 2004, several from that group left for Iraq to fight American troops.
Chérif was arrested as he was about to fly to the Middle East. "He said he was relieved that he got arrested because he was afraid he would get killed in Iraq," his lawyer at the time, Vincent Ollivier, told Le Monde.
Mr. Olliver said Chérif's brother, Saïd, was held for three days but released for lack of evidence.
While behind bars, Chérif befriended Djamel Beghal, who was serving a 10-year sentence. Mr. Beghal was part of a previous generation of Islamists who made news around the time of the Sept. 11, 2001, hijackings.
According to court documents filed in the extradition of one of his associates from Montreal, Mr. Beghal had trained in camps in Afghanistan and was arrested in the summer of 2001. He confessed to heading an al-Qaeda plot to suicide-bomb the U.S. embassy in Paris.
Chérif, Mr. Coulibaly and Mr. Beghal would be in the news again in 2010, in a conspiracy that connected them to an even older breed of terrorists. They were among 14 suspects arrested after police said they had thwarted a plot to free the Algerian bomber Smain Ait Ali Belkacem from prison.
Mr. Belkacem is a former member of the GIA (Groupe islamique armé) Algerian rebel group. He was imprisoned for his role in a wave of bombings in the summer and fall 1995 in France that killed eight people and injured more than 170.
The violence had spread from Algeria, which faced an Islamic insurgency after the military-backed government cancelled an election that the Islamic Salvation Front was set to win.
Mr. Coulibaly got a five-year sentence in the attempted jailbreak. Chérif was luckier: He was released after a stay of proceedings.
By the time of this month's events, the brothers had long been involved with radical groups and lived in brazen fashion in the Paris suburb of Gennevilliers. A neighbour told The Globe and Mail that two months ago she and her husband found a cache of arms inside the Kouachi residence but kept silent after the brothers threatened them.