British Prime Minister Theresa May calls for greater control over the Internet in the wake of Saturday’s terrorist attack. (Will Oliver/European Pressphoto Agency)

— Following the third deadly terrorist attack Britain has suffered in less than three months, Prime Minister Theresa May vowed to review her country’s counterterrorism strategy.

While May condemned what she called the “evil ideology of Islamist extremism,” the thrust of her new counterterrorism demands focused on a far more technical matter: the Internet.

“We cannot allow this ideology the safe space it needs to breed,” May said Sunday, speaking outside 10 Downing Street. “Yet that is precisely what the Internet — and the big companies that provide Internet-based services — provide.”

It has become a common practice among those behind Europe’s terrorist attacks to communicate with one another via encrypted messaging platforms such as Viber and WhatsApp.

In a March vehicle attack outside Parliament that killed four pedestrians and a police officer, the perpetrator, Khalid Masood, 52, was revealed by British media to have been communicating on WhatsApp just minutes beforehand. This prompted Britain’s Home Secretary Amber Rudd to implore that messaging services “don’t provide a secret place for terrorists to communicate with each other.”

It remains unclear, however, whether Masood’s use of WhatsApp was relevant to his crime.

The suicide bombing last month outside a Manchester concert, where 22 were killed, fueled speculation from May and others in the government about the problem of such messaging, but there has been no confirmation the technology played a role.

It is also unclear whether any of the three known assailants in Saturday’s attack relied on encrypted messaging in hatching their plot.

But May argued Sunday for increased government surveillance of cyberspace, already a component of the Conservative Party’s platform in Britain’s upcoming snap election later this week.

“We need to work with allied democratic governments to reach international agreements that regulate cyberspace to prevent the spread of extremist and terrorism planning,” she said. “And we need to do everything we can at home to reduce the risk of extremism online.”

Similarly, her party’s manifesto already has called for a “regulatory framework in law” to “ensure that digital companies, social media platforms and content providers” abide by standards that prevent “abusive behavior.”

In the beleaguered Europe of 2017, having struggled to prevent an unprecedented spike in terrorist violence, May’s proposal is nothing new.

In recent years, variations of cyber-surveillance measures already have been imposed in nations such as France and Germany, more accustomed to the type of violence that now seems to have set its sights on Britain.

The problem, security analysts say, is that these surveillance measures aren’t always effective.

“The technical stuff is important and essential — disrupting these networks, etc. — but all you’re doing there is managing the problem,” said Raffaello Pantucci, a counterterrorism expert at the Royal United Services Institute, a London-based think tank. “And how do you make the problem go away?”

In France, for instance, the country that has endured most of Europe’s recent terrorism, the government passed sweeping surveillance legislation following the January 2015 attack on the editorial offices of Charlie Hebdo.

To the chagrin of information activists, the new laws permit the French government to monitor the private communications of individuals without having secured judicial authorization. Among other things, the laws also require Internet service providers to share metadata with French intelligence services.

Despite the adoption of these laws, even deadlier attacks in France were soon to follow.

In November 2015, 130 people were killed in an Islamic State-orchestrated assault on a concert hall and cafes across Paris. In July 2016, a “lone wolf” attacker, allegedly inspired by the Islamic State, plowed through celebrating crowds on an ocean promenade in Nice, killing 86. A host of smaller-scale incidents have happened periodically since.

The German Parliament adopted a controversial anti-terror surveillance law in October, a measure that, in part, allows the government to intercept communications of foreign nationals and organizations in Germany.

That law took effect earlier this year. But despite earlier surveillance techniques already in place, a Tunisian man who unsuccessfully sought asylum — who had pledged his allegiance to the Islamic State — plowed a truck through a Berlin Christmas market, killing 12.

“You’re dealing with ingrained ideologies and fundamental global shifts and patterns. It’s difficult to imagine how a single Western government can eradicate it,” Pantucci said.

In the wake of Saturday’s attack, it is not clear what prompted the police roundups of 12 people just hours later. Nor is it clear, despite the prime minister’s speech, whether the perpetrators made use of encrypted messaging platforms.

Mark Rowley, London’s assistant police commissioner, said that three assailants had been shot dead at the scene, but that they were not believed to have had accomplices.