ISIS glorifies violence, showing beheaded journalists with the gusto of a Nike ad, ransacks and destroys museums and commits mass slaughters, while frantically awaiting an apocalypse, according to some, such as Atlantic editor Graeme Wood, who has studied its messages carefully.
And while ISIS territorial expansion may have stalled, new groups in countries like Libya and Nigeria have pledged their allegiance to it, raising the question of how the West could combat its underlying message.
"This is no longer about territory, this is about ideas," Heather Gregg, a professor of defence analysis and religious violence at the Naval Postgraduate School in California, said in an interview.
Throughout history, humanity has dealt with contagious ideas preaching brutality and disregard for life. One response to this challenge has involved efforts to convert radicals away from their destructive ideas.
In the 1930s and 1940s, for example, Nazis and their associates systematically murdered millions, announcing that non-Aryan peoples were subhuman.
During the Second World War, when it suddenly became imperative to create new defences against a relentless attack, Western military and civilian agencies deployed a combination of modern sociology, psychology, and technology to focus on ideological change, Kristi Cooper, an Oxford University expert in Second World War counter-ideology, said in an interview.
"It was not so much about changing minds, it was about frustrating ambitions," said Cooper. "It was providing the proper structures and incentives to offer them an alternative future."
Throughout the war, the British captured Nazi prisoners, whom they studied in detail. The British evaluated their motivations and dedication, and focused their attention on those in the grey zone, who were not too adamant about their beliefs.
"This was the chief group whose attitudes could be easily influenced, and influence formation was the objective. These converts were then used to identify others and a key technique was the encouragement of their peers in the belief of an alternative future."
Denazification was concerned with removing those with strong Nazi views from positions of power and this ideological work was concerned with ensuring as much as possible that those useful to the British cause were identified and given positions of influence, said Cooper.
She said the hope for reintegration into the European community was key to Germany leaving behind Nazism and transforming itself into one of the most powerful democracies in Europe.
Today, several programs are in use to combat the ISIS messages.
Extreme Dialogue in Canada and the 77th Brigade in England are two programs Western countries are using to directly combat these ideas from spreading.
In Montreal a tip line is being created so people can report extremists of any kind.
Most deradicalization programs engage in theological debate and some bring in support from families, financial influence, vocational training and mental-health care.
Since there is no way to measure a person's deep beliefs, data is hard to collect and success is difficult to measure.
The messenger is important
Since ISIS draws heavily on religion for recruitment and retention, Gregg thinks religious debate is crucial. But she says the messenger is as important as the message.
She says when secular leaders like Barack Obama, president of the United States, or moderate Muslims try to engage in the religious conversation, they may be reinforcing ISIS's argument that these groups are trying to lead people astray.
The best messengers, she said, are former extremists.
However, Mark Sedgwick, professor of Arab and Islamic Studies at Aarhus University in Denmark, said in an interview that since there isn’t only one reason people join ISIS, individual cases must be treated differently.
"If you've got someone with mental health issues, you want to address those and not engage in a theological debate or a discussion of international relations.
"If you're dealing with a former colonel in Saddam's army ... he's engaging in a particular conflict and that's the point that needs to be addressed."
Much like military intervention, cultural and psychological interventions can have dangerous, unforeseen consequences.
After the British identified and encouraged former Nazis they hoped would promote British values, they saw a number become ardent Communists.
Ribal al-Assad, who is the cousin of Syria's President Bashar al-Assad but opposes him and campaigns for human rights, said in an interview that people in Iraq and Syria who are fighting alongside ISIS don't necessarily believe in the religious fundamentalism of the group but join because they have no other options.
Like denazification, the coalition forces invaded Iraq with the goal of eradicating the influence of Saddam Hussein's party. In doing so, they implemented "debaathification."
Any public sector employee related to Hussein’s secular Baath party was fired. This meant that some 30,000 teachers, judges, politicians and engineers found themselves jobless. On top of that, the coalition dissolved the approximately 500,000-member military.
"ISIS was set up by the Baathists, or former Baathists, because they want to scare the West and they want the West to come talk to them because they (the Baathists) can get rid of them," Ribal al-Assad said.
Maryam Namazie, a human rights activist, says the Western media should discuss and try to combat ISIS as a fascist movement instead of an Islamic one.
"It's sort of portrayed as what people want in the Middle East, North Africa or South Asia and it’s important to show how this movement actually makes inroads by limiting people's rights and by slaughtering people,” Namazie said in an interview.
"It's no longer about the belief, it's about power."
Alyssa McMurtry is a freelance journalist based in Madrid.