After years of Islamist terror attacks from Paris to the Riviera that have left hundreds dead, you might think that the French are inured to the fact that they are the jihadists’ favorite target in the Western world. But now they have been shocked into the realization that the situation is even worse than they thought. Last week’s massacre at the monumental Paris Police Prefecture on the Île de la Cité near Notre-Dame cathedral occurred despite repeated government assurances that all possible measures had been taken to prevent further random slaughter. If one of France’s most secure buildings could be infiltrated by a terrorist, commentators are saying this week, no one is safe anywhere.

“This is a major turning point in Islamist terrorism,” says Gilles Kepel, a specialist in Middle East and jihadist studies. “It’s hard to believe that the police [force], which we rely on to protect us and is supposed to be our last rampart against terrorism, can itself be the victim of terrorism, with throats slit in the holy of holies of the Police Prefecture.”

The attack was also a powerful symbol of France’s ingrained, systemic vulnerability to the jihadists. The two countries’ law enforcement systems are too different for an exact analogy, but it’s a bit as if an FBI special agent at the Bureau’s Joint Terrorism Task Force or a CIA operative in the Counterterrorism Center suddenly ran amok. The implications for French — and Western — security are broad and acutely troubling.

There being no TV-ready gory visuals of mayhem available, the event’s skimpy coverage in the U.S. was predictable. Then, too, the body count was low: “only” four persons were stabbed to death or had their throats cut by a Koran-crazed maniac with a foot-long kitchen knife crying “Allahu Akbar.”

This was small beer for the mainstream media, compared with the January 2015 assault by al-Qaeda operatives at the Paris offices of the satirical, Islam-mocking magazine Charlie Hebdo and a kosher grocery that killed 12. Or in November that year when jihadists killed 130 in separate attacks across the Paris region, beginning with a rock concert massacre. Not to mention the truck-wielding Islamist Mohamed Lahouaiej-Bouhlel, who crushed 86 to death and injured 206 in Nice on Bastille Day 2016. The list goes on: 263 people have been killed in France’s 18 known Islamist attacks in the last six years, including an 86-year-old priest in Normandy stabbed at the altar as he was saying Mass.

But the October 3 murders, carried out in the Prefecture’s intelligence division by a longtime civil servant with a top secret clearance, is not only unprecedented but also simply inconceivable to the stunned French public. Ironically, this is the very National Police office in charge of tracking terrorists, the beating heart of the country’s counterterrorism campaign, and the collection point for data on jihadists in France. Yet it couldn’t detect a terrorist within its own ranks. You couldn’t make this up.

Surveillance cameras in and around the Prefecture helped investigators piece together how Mickaël Harpon, a 45-year-old, Martinique-born computer technician who had worked at the headquarters for 15 years, went about his attack.

Leaving his office at noon for a lunch-hour break, he headed to a local hardware store and bought the kitchen knife and a short-blade oyster knife off the shelf. Returning to the Prefecture, he easily passed through its entrance with his official badge — there was no metal detector. Back in his office, he quickly and expertly slit the throat of his supervisor, a 50-year-old police major, and stabbed a policeman at a nearby desk before he could react. He went to an office on the same floor and stabbed a civilian clerk before descending a stairway and randomly stabbing a policewoman he ran into. On reaching the building’s courtyard he slashed the neck of a female civil employee, who survived. He was stopped by a young trainee policeman who shot Harpon twice as he came at him brandishing the knife. The spree lasted seven minutes.

Confusion reigned in the hours following as government officials and reporters scrambled to make sense of what had happened. President Emmanuel Macron was silent until an official ceremony for the victims held this week, letting his interior minister, Christophe Castaner, take the heat. The minister tried to play down the idea that it could have been a terrorist attack. Harpon, he said, had “never given any reason for alarm or shown any behavioral problems.” He had been well evaluated by his supervisor; Islam had nothing to do with it. Just an ordinary homicide case involving a frustrated employee whose handicap (Harpon was hard of hearing) might have kept him from promotion.

As the facts began to emerge, the conservative opposition called for Castaner’s resignation because either he had lied or he didn’t know what he should have known. In fact, alarm bells had been ringing for years about Harpon. He had converted to Islam in 2015. He told co-workers that those killed at Charlie Hebdo got what was coming to them. (They alerted their hierarchy to this, but bureaucratic blockage kept the information from being acted on; the complaint had to be in writing for official consideration, and they didn’t want to go on record as criticizing a Muslim.) Other danger signs included Harpon’s marriage to a veil-wearing Muslim woman, his sudden refusal to greet his female co-workers with the customary kiss on both cheeks, his donning of traditional Arab garb, and his frequenting a mosque where the imam was a known Salafist firebrand. With top secret clearances being renewed only every seven years, he was under the radar during the entire period of his radicalization.

It’s perfectly possible that Harpon was targeted years ago by jihadists as an ideal plant. He worked in a key counterterrorism department, and as a mere technician rather than an agent or analyst he would be unlikely to draw suspicion. He was vulnerable due to the handicap that left him dissatisfied with his lot. Once he was converted and increasingly radicalized, he was easy to turn into a mole, a member of the jihadist fifth column, a sleeping agent ready to act when the call came.

It was only when examination of his cellphone revealed that he was in touch with Salafist circles that the government officially classed the case as terrorism. As the conservative Le Figaro put it in an unusually hard-hitting editorial, “If we didn’t see this coming, it’s because we didn’t want to. And if we didn’t want to, it’s because we in France are in denial about Islamic extremism. It’s a malady, a deliberate blindness that we can overcome only by admitting it.”

Once the emergency task force of 160 investigators working on Harpon’s computer and other electronic devices crack the sophisticated encryption he used to conceal his activities, they are expected to garner more important information. Meanwhile, a USB memory stick discovered in his office was found to contain al-Qaeda propaganda videos, complete with beheadings. More ominously, it also contains names, addresses, and other personal information on some 250 members of the intel unit, along with their informers, persons currently under surveillance, and undercover police who try to infiltrate radicalized mosques. Their cover is blown.

The great unknown is how much of this top-secret information was delivered to jihadists and hostile foreign governments. “Besides having a top-secret clearance, he was the administrator of the whole network,” an Interior Ministry source says. “He had access to everything.” This could hobble counterterrorism worldwide. How many intelligence agencies, from the CIA to Britain’s MI6 to Germany’s Bundeskriminalamt and Israel’s Mossad, will now balk at sharing data with France?

The inevitable effect of this episode on the police is apprehension and plunging morale. (The young officer who shot Harpon has requested a transfer, saying he feared for his life at the Prefecture.) It was bad enough before this happened — so far this year, over 50 policemen have committed suicide. With its overstretched members called on to manage Gilets Jaunes demonstrations nearly every weekend this year, the government owes officers some 25 million euros (sic) in overtime compensation which it has not paid. “We would at least like to be assured that any police officers mentioned in Harpon’s data have been warned,” says the head of a police union. “They may need to move to new homes and take other measures to protect their families.” Three years ago, a married couple, both with the police, were killed in their suburban Paris home by an Islamic terrorist who found their addresses on a memory stick.

Just how far has France been infiltrated? Last June, a parliamentary report on radicalization within France’s public sector said that 30 members of the police and gendarmerie were suspected of Islamic leanings and were under surveillance. Fifteen of those were in the Paris Prefecture. In addition, the report found that as many as 80 employees at the Paris airports Charles de Gaulle and Orly were Islamists who had access to baggage handling and similar sensitive zones.

Other areas known to have radicalized personnel include hospitals, schools, and public transport. But they can’t be fired because France’s liberal dogma means they must commit a crime before action is taken. Otherwise, the government would be accused by activists of discrimination and religious persecution. Because of its policy of laïcité, or secularism, France officially has no minorities. Everyone is French and by definition equal. Statistics based on race or religion are prohibited.

It’s obvious that the country is under a determined jihadist onslaught. Less clear is whether its leaders, behind the curve due to years of failing to come to grips with the problem and paralyzed by fear of being labeled Islamophobic racists, have the political courage to defend it.

Joseph A. Harriss is The American Spectator’s Paris correspondent. His latest book is Jean Gabin: The Actor Who Was France (McFarland).