Religion is not the strongest driving force behind thousands of foreign fighters joining Isis and other terrorist groups in Iraq and Syria, a report by US military researchers has found.

A new study by the Combating Terrorism Center (CTC) at West Point revealed that the vast majority of almost 1,200 militants surveyed had no formal religious education and had not adhered to Islam for their entire lives.

Extremist groups may prefer such recruits because they are “less capable of critically scrutinising the jihadi narrative and ideology” and instead adhere totally to their chosen organisation’s violent and reductive interpretation of Islam.

Isis' radicalisation of foreign fighters

Analysts said many foreign fighters travelling from the West are attracted to jihadi groups through cultural and political identities rather than Islam itself, which is moved into a “secondary role”.

“The ability of jihadi groups to recruit foreign fighters is thus based on creating a narrative that is focused on the ongoing deprivation of Muslims, both in specific Western polities, as well as in the international arena,” said the CTC’s report.

The analysis, carried out at the United States Military Academy, corresponded with revelations from a trove of Isis entry forms leaked earlier this year, where the majority of those joining the so-called Islamic State listed their Sharia knowledge as “basic”.

At the height of Isis’s drive for foot soldiers in 2013 and 2014, recruits reportedly included two Britons who ordered The Koran for Dummies and Islam for Dummies from Amazon to prepare for jihad abroad.

Major Islamic organisations around the world have condemned Isis and ripped it's theological claims to shreds. Among them is the Muslim Council of Britain, which issued a joint statement from mosques across the UK condemning the group's “deceitful” actions as “far from the teachings of Islam”.

While government-led strategies across Europe and the US have encouraged mosques to take a lead in fighting radicalisation, the CTC found that religious figures played only a “minimal role” and fighters were isolated from Muslim communities at home, instead being radicalised by jihadi recruiters, online or by friends.

The CTC analysed the lives – and deaths – of foreign fighters who attempted to join militant groups in Syria and Iraq from 2011 to 2015, from France, Belgium, the UK, Germany the Netherlands and 25 other countries.

“Foreign fighters are not just engaging in a significant amount of fighting, but they are also doing a large amount of dying,” said the report.

Western foreign fighters studied by the CTC by country (CTC)

At least 74 per cent of those surveyed had been killed in action, although experts warned the number could be skewed by the fact identities of dead foreign fighters are more likely to be in the public domain than those still in action.

Three-quarters of British fighters in the sample had been killed, with the death rate standing at 66 per cent for Isis and 77 per cent for al-Qaeda’s affiliate Jabhat al-Nusra, which has now renamed itself as Jabhat Fateh al-Sham after supposedly splitting from its parent organisation.

Death tolls in Syria and Iraq are almost impossible to confirm, with the absence of impartial authorities on the ground and warring propaganda messages from groups battling for control.

In May this year, the UK-based Syrian Observatory for Human Rights (SOHR) estimated that more than 47,000 foreigners had been killed fighting for anti-Assad factions, including Isis and Jabhat al-Nusra – surpassing the total figure believed to have travelled to the country by the US government.

The Pentagon estimates that its air strikes alone have killed 45,000 Isis fighters, including foreigners and locals.

The CTC found there was no single “profile” for the extremists, although most were aged in their 20s, were unemployed or students and had an immigrant background.

Previous studies have revealed that many also have a criminal past, such as involvement in minor gang crime, which can be preyed on by recruiters presenting a “redemption narrative” to exploit skills valuable to undercover networks.

Westerners are used in a variety of roles depending on their experience, the CTC said, often being sent to terrorist training camps upon arrival in the region before being deployed as soldiers, suicide bombers, leaders or support personnel.

Foreign fighters can also be valuable propaganda tools, such as the British Isis fighter Mohammed Emwazi, who became known as Jihadi John after appearing in a series of gory execution videos showing the murder of James Foley and other hostages.

Timeline: The emergence of Isis Show all 40 1 /40 Timeline: The emergence of Isis Timeline: The emergence of Isis 2000 Abu Musab al-Zarqawi (pictured here) forms an al-Qaeda splinter group in Iraq, al-Qa’eda in Iraq. Its brutality from the beginning alienates Iraqis and many al-Qaeda leaders. Timeline: The emergence of Isis 2006 Al-Zarqawi is killed in a U.S. strike. Al-Zarqawi’s successor, Abu Ayyub al-Masri, announces the creation of the Islamic State in Iraq (ISI). Reuters Timeline: The emergence of Isis 2009 Still al-Qaeda-linked ISI claims responsibility for suicide bombings that killed 155 in Baghdad, as well as attacks in August and October killing 240, as President Obama announces troop withdrawal from Iraq in March. Getty Images Timeline: The emergence of Isis 2010 Abu Bakr al-Baghdadi becomes head of ISI, at lowest ebb of Islamist militancy in Iraq, which sees last U.S. combat brigade depart. Timeline: The emergence of Isis 2012 In Syria, protests (pictured here starting in Daree) have morphed into what president Assad labelled a “real war” with emergence of a coalition of forces opposed to Assad’s regime. Syria group Jabhat al-Nusra are among rebel groups who refuse to join, denouncing it as a “conspiracy”. Bombings targeting Shia areas, killing more than 500 people, spark fears of new sectarian conflict. Sunni Muslims stage protests across country against what they see as increasingly marginalisation by Shia-led government. AP Timeline: The emergence of Isis 2013 Al-Baghdadi renames ISI as the Islamic State in Iraq and Syria, or Isis, as the group absorbs Syrian al-Nusra, gaining a foothold in Syria. In response, al-Qaeda chief Ayman al-Zawahiri (Bin Laden’s successor) concerned about Isis’ expansion orders that Isis be dissolved and ISI operations should be confined to Iraq. This order is rejected by al-Baghdadi. AFP Timeline: The emergence of Isis 2014 - January Isis fighters capture the Iraqi cities of Fallujah and Ramadi, giving them base to launch slew of attacks further south. AP Timeline: The emergence of Isis 2014 - June Isis declares itself the Caliphate, calling itself Islamic State (IS). The group captures Mosul, Iraq’s second largest city; Tal Afar, just 93 miles from Syrian border; and the central Iraqi city of Tikrit. These advances sent shockwaves around the world. Timeline: The emergence of Isis 2014 - June Around the same time Isis releases a video calling for western Muslims to join the Caliphate and fight, prompting new evaluations of extremists groups social media understanding. Timeline: The emergence of Isis 2014 - June Isis take Baiji oil fields in Iraq - giving them access to huge amounts of possible revenue. EPA Timeline: The emergence of Isis 2014 - August James Foley is executed by the group as concerns grow for second American prisoner, fellow reporter Steven Sotloff. AP Timeline: The emergence of Isis 2014 - August Obama authorises U.S. airstrikes in Iraq, helping to stall Isis’ along with action by Kurdish forces following the deaths of hundreds of Yazidi people on Mount Sinjar. Timeline: The emergence of Isis 2014 - September Isis release video showing Steven Sotloff’s murder prompting Western speculation his executioner is same man who killed Mr Foley. EPA Timeline: The emergence of Isis 2014 - September Obama tells us that America “will hunt down terrorists who threaten our country” EPA Timeline: The emergence of Isis 2014 - September Isis release a video appearing to show David Haines, who was captured by militants in Syria in 2013, wearing an orange jumpsuit and kneeling in the desert while he reads a pre-prepared script. It later shows what appears to be the aid worker's body. Rex Timeline: The emergence of Isis 2014 - September Peshmerga fighters scrabble to hold positions in the Diyala province (a gateway to Baghdad) as Isis fighters continue to advance on Iraqi capital. AFP Timeline: The emergence of Isis 2014 - October Aid worker Alan Henning is killed. Self-imposed media blackout refuses to show images of him in final moments, instead focuses upon humanitarian care. AP Timeline: The emergence of Isis 2014 - October Isis raise their flag in Kobani, which had been strongly defended by Kurdish troops. The victory goes against hopeful western analysis Isis had overextended itself, while alienating much of the Muslim population through the murder of Henning. Victory causes fresh waves of Kurdish refugees arriving in Turkey. Timeline: The emergence of Isis 2014 - November American hostage, who embarced values of Islam, Peter Kassig and 14 Syrian soldiers are shown meeting the same fate as other captives. But intelligence agencies will be poring over the apparently significant discrepancies between this and previous films. Seramedig.org.uk Timeline: The emergence of Isis 2015 - February Isis has released a video revealing the murder by burning to death of a Jordanian pilot held by the group since the end of December 2014. Reuters Timeline: The emergence of Isis 2015 - February Isis militants have released videos which appear to show the beheading of Japanese hostages Haruna Yukawa and Kenji Goto. Timeline: The emergence of Isis 2015 - February American aid worker, Kayla Mueller was the last American hostage known to be held by Isis. She died, according to her captors, in an airstrike by the Jordanian air force on the city of Raqqa in Syria, though US authorities disputed this. AP Timeline: The emergence of Isis 2015 - February Isis militants have posted a gruesome video online in which they force 21 Egyptian Coptic Christian hostages to kneel on a beach in Libya before beheading them. Egypt vowed to avenge the beheading and launched air strikes on Isis positions. AP Timeline: The emergence of Isis 2015 - February The British Isis militant suspected of appearing in videos showing the beheading of Western hostages has been named in reports as Mohammed Emwazi from London. Rex Features Timeline: The emergence of Isis 2015 - March Isis triple suicide attack has killed more than 100 worshippers and hundreds of others were injured after the group members targeted two mosques in the Yemeni capital of Sanaa. AP Timeline: The emergence of Isis 2015 - April Iraqi forces have claimed victory over Isis in battle for Tikrit and raised the flag in the city. EPA/STR Timeline: The emergence of Isis 2015 - April Isis has claimed responsibility for a suicide bomb attack in Afghanistan that killed at least 35 people queuing to collect their wages and injured 100 more. EPA Timeline: The emergence of Isis 2015 - April Isis’ media arm released a 29-minute video purporting to show militants executing Ethiopian Christians captives. The footage bore the extremist group’s al-Furqan media logo and showed the destruction of churches and desecration of religious symbols. A masked fighter made a statement threatening Christians who did not convert to Islam or pay a special tax. Timeline: The emergence of Isis 2015 - May Abu Bakr al-Baghdadi, the leader of Isis has been "incapacitated" by a spinal injuries sustained in a US air strike in Iraq. He is being treated in a hideout by two doctors from Isis’ stronghold of Mosul who are said to be "strong ideological supporters of the group". Timeline: The emergence of Isis 2015 - May Isis has also claimed responsibility for killing 300 of Yazidi captives, including women, children and elderly people in Iraq AP Timeline: The emergence of Isis 2015 - May Isis attack on Prophet Mohamed cartoon contest in Texas was its first action on US soil. Two gunmen were shot and killed after launching the attack at the exhibition. Elton Simpson and Nadir Soofi have been named as the attackers at the Curtis Culwell Centre arena in Garland. Timeline: The emergence of Isis 2015 - May Isis’s deputy leader, Abu Alaa Afri, a former physics teacher who was thought to have taken charge of the deadly terrorist group, has been killed in a US-led coalition airstrike. Timeline: The emergence of Isis 2015 - May US special forces have killed a senior Isis leader named as Abu Sayyaf in an operation aiming to capture him and his wife in Syria. Getty Images Timeline: The emergence of Isis 2015 - May Iran-backed militias are sent to Ramadi by the Iraqi government to fight Isis militants who completed their capture of the city. Government soldiers and civilians were reportedly massacred by extremists as they took control and the army fled. Charred bodies were left littering the city streets as troops clung on to trucks speeding away from the city. Ramadi is the latest government stronghold to fall to the so-called Islamic State, despite air strikes by a US-led international coalition aiming to stop its advance in Iraq and Syria. AFP Timeline: The emergence of Isis 2015 - May Isis rounded up civilians trapped in Palmyra and forced them to watch 20 people being executed in the historic city’s ancient amphitheatre. The Unesco World Heritage site was overrun by militants, threatening the future of 2,000 year-old monuments and ruins. Thousands of Palmyra’s residents fled but many are still living within the city walls, while the UN human rights office in Geneva said it had received reports of Syrian government forces preventing people from leaving until they retreated from the city. Getty Timeline: The emergence of Isis 2015 - May A group of Isis-affiliated fighters have captured a key airport in central Libya. The militants took control of the al-Qardabiya airbase in Sirte after a local militia tasked with defending the facility withdrew from their positions. Affiliates of Isis, already control large parts of Sirte, the birthplace of former Libyan leader Muammar Gaddafi and a former stronghold of his supporters. Timeline: The emergence of Isis 2015 - June The US Air Force has destroyed an Isis stronghold after an extremist let slip their location on social media. According the Air Force Times, General Herbert "Hawk" Carlisle, commander of Air Combat Command, said that Airmen at Hulburt Field, Florida, used images shared by jihadists to track the location of their headquarters before destroying it in an airstrike. Reuters Timeline: The emergence of Isis 2015 - June Kurdish forces captured a key military base in a significant victory in Raqqa as well as town of Tell Abyad. YPG fighters, backed by US-led airstrikes and other rebels, consolidated their gains, when they seized the key town on the Syria-Turkey border. They are now just 30 miles to the north of Raqqa and have cut off a major supply route deep inside Isis-held territory. Ahmet Silk/Getty Timeline: The emergence of Isis 2015 - June Isis has released gruesome footage claiming to show the murder of more than a dozen men by drowning, decapitation and using a rocket-propelled grenade as it seeks to boost morale among its fanatical supporters. Timeline: The emergence of Isis 2015 - June Isis has begun carrying out its threat to destroy structures in the ancient Syrian city of Palmyra, blowing up at least two monuments at the Unesco-protected site as Syrian government troops made advances on the Islamist’s positions. AFP

Isis frequently uses European recruits for videos aiming to incite attacks in their home countries and there is growing concern over the potential use of foreign fighters who return, complete with weapons training and battlefield experience.

“For some, exposure to violence may serve to harden their belief in the organization on behalf of which they are working,” the CTC’s report said.

“For others, the brutal realities of the battlefield may be the first step in their disenchantment with an organisation.

“Wrestling with how to distinguish between returnees who are hardened as opposed to those who are disillusioned, as well as what to do in either case, is a challenge that will only grow larger as fighters return in greater numbers and governments struggle to respond.”

Among the Isis recruits who returned to Europe last year is Harry Sarfo, who grew up in the UK and travelled to join the group in Syria after meeting a radical preacher during a jail term for robbery.

Now in prison, he told The Independent said the stonings, beheadings, shootings, executions and use of child soldiers he witnessed drove him to flee the group after finding its ideology to be “un-Islamic”.

“My worst memory is of the execution of six men shot in the head by Kalashnikovs,” Sarfo recalled.

“The chopping off of a man’s hand and making him hold it with the other hand.

Western foreign fighters studied by the CTC by group (CTC)

“The Islamic State is not just un-Islamic, it is inhuman. A blood-related brother killed his own brother on suspicion of being a spy. They gave him the order to kill him. It is friends killing friends.”

The CTC said only 10 per cent of the fighters they assessed had returned, with the risk of them being used in future terror operations rising the longer they stay in extremist-held territory.

Analysts warned that while an estimated 90 per cent of militants were arrested after arriving back in the West, others slip through the gaps and pose a diverse and deadly threat.

Trained Isis fighters were behind terror attacks at the Jewish Museum of Belgium in 2014, the 2015 Paris attacks and Brussels bombings earlier this year as well as several other plots, with the group’s propaganda inspiring “lone wolf” attacks such as the atrocity that killed more than 80 people in Nice.

“While the direct return and execution of attacks is an important concern, the data here has shown that is far from the only concern,” the CTC’s report concluded.