It can be difficult to divine the precise role that international terrorists play in this or that attack. For example, the person who killed four U.S. Marines and a sailor in Chattanooga, Tennessee, in July 2015 was "motivated by foreign terrorist organization propaganda,"
FBI Director James Comey said, though he added that it's hard to say which terrorist group motivated the killer.
It also can be hard to get precise information about some attacks, but it's clear the deadly tentacles of ISIS have spread quickly from the terrorist group's epicenter in Iraq and Syria to points around the globe.
Here's a look at terrorist attacks outside Iraq and Syria believed to have been inspired or conducted by ISIS or its regional affiliates, along with context about the known connections to ISIS:
October 20, 2014
-- Martin Rouleau-Couture
runs over two soldiers, killing one, outside a government office in Saint-Jean-sur-Richilieu, Quebec. Rouleau-Couture had converted to Islam and expressed support for ISIS online. He may have been responding to ISIS spokesman Abu Muhammad al-Adnani's call to arms, according to the Institute for the Study of War.
ISIS mentioned Rouleau-Couture in its English-language magazine Dabiq, claiming the attack resulted from Adnani's call. It also included a picture of Rouleau-Couture in the magazine. The attack is believed to have been inspired by ISIS.
October 22, 2014
-- Gunman Michael Zehaf-Bibeau opens fire
at Canada's National War Memorial and Parliament Hill in Ottawa, killing army reservist Cpl. Nathan Cirillo. Zehaf-Bibeau is killed by House of Commons Sergeant-at-Arms Kevin Vickers. Two others, including a security guard, are injured. ISIS mentioned Zehaf-Bibeau in Dabiq, claiming that the attack was the "direct result of (Adnani's) call to action," the Institute for the Study of War reported
. The attack is believed to have been inspired by ISIS.
October 23, 2014 --
A man with a hatchet attacks four police officers
in New York. Police said the attacker, a U.S. citizen named Zale Thompson, was self-radicalized. Thompson had searched online for information on beheadings, al Qaeda, ISIS and al Shabaab, according to police. ISIS mentioned Thompson
in Dabiq, according to the Institute for the Study of War. The attack is believed to have been inspired by ISIS.
May 3, 2015 --
Two men open fire outside a Prophet Mohammed cartoon contest
in a Dallas suburb. The gunmen, Elton Simpson and Nadir Soofi,
wound a security guard before police shoot and kill them. Simpson linked himself to ISIS in a tweet posted before the attack, according to a federal law enforcement source.
The keynote speaker at the event was right-wing Dutch politician Geert Wilders, who was on an al Qaeda hit list. At least one of the gunmen appeared to have been in contact with an ISIS operative in Syria via social media. ISIS claimed responsibility, describing the attackers as "soldiers of the caliphate,"
according to the Institute for the Study of War. The institute described the attack as "ISIS-inspired," and U.S. officials said the group probably was being "opportunistic" in claiming responsibility. The attack is believed to have been inspired by ISIS.
November 4, 2015 --
University of California, Merced, student Faisal Mohammad stabs four people
before being shot to death by police. Authorities initially said the attack was simply the work of a disgruntled student, but the FBI concluded four months later that Mohammad had looked at ISIS and other terrorist websites and propaganda before the attack. The agency concluded the attack appeared to be terror-inspired, but said "it may never be possible to definitively determine why he chose to attack people on the UC Merced campus." None of the stabbing victims died.
December 2, 2015 --
Tashfeen Malik and her husband, Syed Rizwan Farook, shoot 14 people to death
and injure 21 others at a gathering of local government health workers in San Bernardino, California. Malik and Farook are gunned down in a shootout with law enforcement.
Malik pledged allegiance to ISIS leader Abu Bakr al-Baghdadi on Facebook, three U.S. officials familiar with the investigation told CNN.
The husband-and-wife team had developed extremist views
as early as 2013, a time that predates the rise of ISIS, FBI Director Comey has said. And Farook tried to contact other terrorist groups, a senior law enforcement official said.
"Individuals inspired by the Islamic State of Iraq and al Sham (ISIS) and with links to al Qaeda conducted the terrorist attack," according to the Institute for the Study of War.
"This attack was the first al Qaeda- or ISIS-related in the U.S. by a skilled shooter team using both guns and explosives." The attack is believed to have been inspired by ISIS.
January 8, 2016 -- A man identified as Edward Archer is arrested after a Philadelphia police officer is shot and wounded. Officer Jesse Hartnett was hit three times and suffered "some very serious injuries that will require multiple surgeries," Philadelphia Police Commissioner Richard Ross said. Despite being seriously injured, Hartnett got out of his patrol car and shot the assailant, who later was apprehended by other officers, Ross said.
Archer claims to have committed the attack on ISIS' behalf, telling police: "I pledge my allegiance to the Islamic State, and that's why I did what a did." Archer has a criminal history and impending court appearances. He had traveled to Saudi Arabia and Egypt.
June 12, 2016 -- A gunman killed 49 people at the Pulse nightclub in Orlando, Florida. The shooter, Omar Mateen, was killed by police three hours after taking hostages in the club. Mateen was a 27-year old U.S. citizen of Afghan descent who pledged allegiance to ISIS in a 911 phone call during the siege. Subsequent analysis of his computer shows he was also an admirer of al Qaeda cleric Anwar al Awlaki.
President Obama said there was no evidence the attacker was under direction from a terrorist network, or carrying out any group's larger plot. ISIS media outlet Al-Bayan later described Mateen as "one of the soldiers of the Caliphate in America," but the group provided no evidence of communication with the attacker. The attack is believed to have been inspired by ISIS.
May 24, 2014
--Three people are killed and another seriously injured in a shooting at the Jewish Museum
in Brussels, Belgium. The suspect was identified as Mehdi Nemmouche
, a 29-year-old Frenchman from Roubaix in the Pas-de-Calais region of northern France. Nemmouche, who had spent a year in Syria, is a radicalized Islamist, according to the chief prosecutor of Paris.
Nemmouche was arrested with a Kalashnikov, a handgun, an audio recording claiming responsibility and a white sheet emblazoned with the name of the Islamic State of Iraq and the Levant, according to the Institute for the Study of War.
The attack is believed to have been inspired by ISIS.
December 20, 2014
- A man stabs three police officers
in the French city of Tours. The attacker was a 20-year-old French citizen who was born in Burundi. He was shot dead by police. CNN terrorism analyst Paul Cruickshank reported that the attacker had posted the ISIS flag on his Facebook page. The attack is believed to have been inspired by ISIS.
January 9, 2015
- Amedy Coulibaly is killed
during a police rescue operation to end his siege at a kosher grocery store in Paris. Authorities say he killed four hostages. He allegedly shot a Paris policewoman the previous day. Coulibaly had pledged his allegiance to ISIS in a video made before the attack. He was a friend of Said and Cherif Kouachi, who killed 12 people two days earlier in an attack on the offices of Charlie Hebdo magazine in Paris. Al Qaeda in the Arabian Peninsula claimed responsibility for the attack at Charlie Hebdo.
Pro-ISIS sources circulated a video in which Coulibaly pledged allegiance to ISIS leader
Abu Bakr al-Baghdadi in front of an ISIS flag, according to the Institute for the Study of War. Investigators found ISIS flags, automatic weapons
, detonators and cash in an apartment rented by Coulibaly outside Paris. The attack is believed to have been inspired by ISIS.