A spate of terrorist attacks in Canada and New York City last week appears to have been inspired by calls from Islamic State and other militants to launch lone-wolf attacks that could signal the rise of a kind of DIY terrorism, sowing fear on a smaller but more pervasive scale.
Last month a spokesman for Islamic State urged followers to attack Western and Arab targets "from your place wherever you may be." Eschewing the large and organized attacks that have characterized terrorism of the recent past, he instead recommended killing by any means.
"If you are not able to find an IED [improvised explosive device] or a bullet … smash his head with a rock, or slaughter him with a knife, or run him over with your car, or throw him down from a high place, or choke him, or poison him," said the spokesman, Abu Muhammad Adnani. "If you are unable to do so, then burn his home, car or business. Or destroy his crops."
That directive appears to have been underscored by the weapons used in last week's attacks.
On Oct. 20 in Quebec, Martin Couture-Rouleau ran over two soldiers with his car, killing one. Two days later, Michael Zehaf-Bibeau fatally shot a soldier standing guard at the war memorial in Ottawa, using what police described as "an old and uncommon gun," then drove to Parliament, where he was able to enter the building. The next day in New York City, Queens resident Zale Thompson attacked four police officers with an 18-inch hatchet, striking one in the arm and another in the head.
All three men were shot and killed during the attacks or soon after. Law enforcement and security officials have said the men acted alone and appeared to be self-radicalized.
"In many respects, this is the hardest terrorist threat to detect and the one I worry most about," Homeland Security Secretary Jeh Johnson said last month in written testimony for a congressional hearing.
On Tuesday, Johnson announced enhanced security at various government buildings across the U.S. He directed state and local governments and law enforcement "to be equally vigilant, particularly in guarding against potential small-scale attacks by a lone offender or a small group of individuals."
Atty. Gen. Eric H. Holder Jr. has said that the threat of such attacks keeps him up at night.
On Monday, Canadian lawmakers introduced legislation that, if passed, would expand the global surveillance capabilities of the Canadian Security Intelligence Service, akin to the CIA, as well as allow the government to more quickly implement rules for revoking citizenship of dual citizens who have been convicted of terrorism and other crimes.
Couture-Rouleau, who had been stopped while trying to leave for Turkey in July, was on a list of 90 people being tracked by the Royal Canadian Mounted Police on suspicion of taking part in militant activities abroad or planning to do so. Canadian Public Safety Minister Steven Blaney said the attack "is clearly linked to terrorist ideology."
So far the authorities have been less clear on what motivated Zehaf-Bibeau. The Royal Canadian Mounted Police force, which has a video that Zehaf-Bibeau prepared just before he carried out the attack, said Sunday that it has "persuasive evidence" that he was driven by ideological and political motives.
"One of the problems is that the Internet as well as certain specific Muslim extremists are really firing up this lone-wolf phenomenon," Sen. Dianne Feinstein (D-Calif.), who chairs the Senate Intelligence Committee, said Sunday on CNN's "State of the Union." "And the multiplicity of attacks in 2014 show that their propaganda is having some effect."
Adnani's exhortations to would-be attackers were delivered in September in an audio recording. He encouraged individuals to kill citizens of Western countries, especially those that have joined the U.S.-led campaign against Islamic State targets in Iraq and Syria.
He specifically urged followers to target soldiers, police, security and intelligence officers, and civilians, deeming them guilty for belonging to a nation waging war against the militants.
Days earlier, an anonymous poster published a 17-page screed on a militant website calling on Muslims in the United States to engage in "open source jihad."
"An aggressive and sustained campaign of lone-wolf attacks is the answer to Obama's war on Islam," it read.
Parts of the screed read almost like the transcript for a business venture infomercial. A checklist begins with the question "Why lone-wolf attacks are the best bet now for you?" and goes on to list such benefits as "no training … required," "no funding required," "impossible to thwart" and "you can act on any scenario you might think up. You are in control. You think 'outside the box.'"
Just after the attacks in Canada, Twitter users, some of whom claim to be members of Islamic State living in Syria, praised the killings and encouraged further attacks in retaliation for Canada joining the U.S.-led coalition, according to the SITE Intelligence Group, which monitors online activity by militants.
"I'm afraid we will see more of this," said Rita Katz, SITE director.
Lone-wolf attacks have long challenged intelligence agencies.
"There have been quite a few lone-wolf attacks stretching back 10 years," said Mahan Abedin, a terrorism researcher and co-editor of "Unmasking Terror: A Global Review of Terrorist Activities."
Even Al Qaeda, which has staked its reputation on launching big terrorist attacks, has in the past directed its adherents to remain in their own countries and carry out lone-wolf attacks. With intelligence capabilities more advanced than just 10 years ago and numerous alleged plots having been thwarted, these solo attacks could become the future of terrorism.
"The type of highly coordinated and well-funded attacks we have seen in the past by Al Qaeda are virtually impossible to carry out in the West now because of the branches of counter-terrorism," Abedin said.
By contrast, lone-wolf attacks are easy and cheap to carry out even while they sow fear and undermine a nation's sense of security, especially because they are the most difficult to prevent.
But Islamic State has achieved wider resonance than Al Qaeda ever did, in part because its mass use of social media has attracted more disaffected youth even as its message of an ultra-conservative Islamic caliphate, with control over large swaths of territory and the beginnings of an actual nation state, has broadened its appeal beyond just the radicalized and militant.
"The pull and influence they are having, I think that's what's different here," said terrorism analyst Evan Jendruck at IHS Jane's Terrorism and Insurgency Center.
Social media sites are replete with "fanboys" praising the Islamic State, imams or other religious figures voicing support or militant groups pledging allegiance. That wide influence that could make its current call for individual attacks more effective.
"The ISIS phenomena is something very different, it's grass roots," said Katz, using an acronym for the group. "The call now to ISIS supporters is just go and kill.... The message is: Stay in your country, do what you can do and do it quickly."