As Parisians struggle to understand why anyone would turn their city into a killing field, security experts around the world and here in Canada are pondering another question: How?

How could a series of coordinated attacks like the one seen on Friday in the French capital have been planned and executed without anyone noticing?

How could weapons not readily available in France have reached the eight known assailants?

How could people sympathetic to the cause of the Islamic State, which has claimed responsibility, have been recruited and trained in secret?

The answers, when they come, may not cast a very flattering light on France’s intelligence agencies, said the University of Ottawa’s Wesley Wark, one of Canada’s leading experts on national security, intelligence and terrorism.

“It is a well-structured and very powerful intelligence service, which just adds to the mystery,” Wark noted, adding that France’s security sector has some of the globe’s most intrusive surveillance powers. Tweet This

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“This attack was planned from abroad, coordinated and conducted from abroad, and it’s precisely that type of large-scale intricate attack that you hope large-scale security agencies are going to be able to detect and prevent.”

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As of Saturday, the official death toll across seven known attack sites in Paris stood at 129. Hundreds more victims were being treated in hospital, with some in critical condition.

There is, as of yet, no indication that French security services knew enough about the attacks and their timing to prevent the mass casualties, but the fact that French President François Hollande said the group responsible had already been identified on Saturday has led security experts to suggest that there was at least some advance warning.

Was France overwhelmed?

Christian Leuprecht, professor of political science at the Royal Military College of Canada and senior fellow at the Macdonald Laurier Institute, said it’s possible the French were overwhelmed by the sheer volume of security work currently being carried out.

“In the aftermath of Charlie Hebdo, we learned that French security services are following some 6,000 people and there’s simply not enough resources to follow 6,000 people 24/7,” Leuprecht said.

“Perhaps this is a case where the resources were not allocated in the right fashion.” Tweet This

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But Wark says he doesn’t buy that explanation.

“The reality is that security and intelligence services are always overstretched,” he said. “I don’t think that argument goes very far … I don’t find it convincing.”

What will this mean for Canada?

Closer to home, Prime Minister Justin Trudeau, currently in Turkey for a G20 summit, told reporters that he was taking steps to ensure the security of Canadians but did not give specifics. The prime minister has also been briefed by Canadian intelligence agencies in the wake of the Paris attacks. It is unclear if the domestic threat level has changed.

The RCMP has said it is watching for copycats on Canadian soil, and a spokesperson for the Public Safety department said that “while we do not comment on operational matters related to national security, we can say that the Government of Canada is closely monitoring the situation in Paris.”

READ MORE: ISIS claims responsibility for Paris attacks; France remains the ‘top of the list of targets’

Britain’s prime minister, meanwhile, has announced that his country’s domestic threat level will remain at “severe” (the second highest threat level on their scale) while France has bumped its own to the highest level possible.

The lack of a publicly disclosed threat level in Canada points to the fact that these systems are largely used to coordinate action among multiple security agencies and stakeholders, Leuprecht said. Our security services have largely been centralized in Ottawa and already have good communication.

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While Canadians might expect more visible security on their streets in response to what happened in Paris, Wark said that’s not the best way to prevent a similar, multi-pronged attack here at home. What Canada will do, he predicted, is continue to shore up intelligence-gathering resources.

“Canadian security officials will be streaming to Paris,” Wark said. “To offer assistance, to learn what they can from the French investigation, to track down any leads.”

Leuprecht agreed.

“Western intelligence services are going to be working overtime on the weekend to see what connections there might be from these attackers to the rest of the world,” he said. Tweet This

“President Hollande said these attacks were planned in Syria … that planning cell might also have reached back into other countries … the Canadian government will be studying both (anti-terror bill) C-51 and the national security regime we have in place very carefully after these attacks.”