It’s a diverse, fast-growing organisation with an expanding bureaucracy. Integrating its well-educated, multilingual workforce is a major headache, but its leaders are preoccupied with ensuring it harnesses the skills and talents of its many inexperienced recruits.

These are the growing pains not of a successful tech start-up but of Islamic State, the apocalyptic jihadist group that has laid claim to vast swathes of territory across Syria and Iraq while spawning affiliates in north Africa and south Asia.

The insights are contained in a cache of Islamic State personnel records obtained by international media last month.

The documents, which were produced primarily between early 2013 and late 2014, provide new insights into the background and motivation of thousands of foreign fighters who joined the group, which is also known as Isis, in that period.

A study of the haul by the Combating Terrorism Center, a research and policy institution at the United States Military Academy in West Point, New York, found that the 11,000 files leaked by an Isis defector in March contained 4,600 individual records.

The centre said it was able to cross-reference the documents against a pre-existing repository of Islamic State records held by the US Department of Defence, allowing it to corroborate 98 per cent of the leaked files.

Fighter from Ireland

The records largely comprise standardised forms filled out by new arrivals in Islamic State-controlled territory in Syria, although some appear to have been filled in by officials on their behalf.

The forms list responses to questions on citizenship, previous occupations, education levels, religious knowledge, previous jihadist experience and other topics.

The fighters came from over 70 countries, with Saudi Arabia, Tunisia, Morocco, Turkey and Egypt making up the top five countries of origin.

France was the highest-ranking western state, with 49 new recruits listed as having come from there, but also high on the list were Albania (42), Germany (38), Kosovo (32), the UK (26) and Belgium (9). One recruit listed Ireland as country of residence.

The average recruit was 26-27 years old, but one was in his late 60s and 41 were 15 or younger when they arrived. Educational backgrounds varied, but as a whole the group was relatively well-educated when compared to education levels in their home countries, the centre noted in a report on its analysis.

The second most populated education category was those with college-level education

When recruits were asked about their work experience, however, the largest cohort had been in low-skilled employment. “This is an interesting juxtaposition to the educational profile and raises intriguing questions about the possibility that some fighters in the dataset may have been motivated by frustration over failure to achieve expected success in the job market following their education,” the report observes.

There are no reliable figures on the number of foreigner fighters in Islamic State's ranks. In February 2015, US Director of National Intelligence James Clapper said the group could count on between 20,000 and 32,000 fighters in Iraq and Syria, although it is believed that there has been high attrition in its ranks since then.

Suicide role

About 10 per cent of the recruits listed in the leaked files stated that they had previous jihadist experience, primarily with other groups in Syria, Libya and Afghanistan.

The Al-Qaeda affiliate Jabhat al-Nusra was one of the most commonly referenced groups that recruits had left to join Islamic State.

The forms invited new fighters to select the type of activity they wished to get involved in. Only 12 per cent expressed a preference for a suicide role over a more conventional fighting role. Those who claimed advanced knowledge of sharia (Islamic law) were less likely to express a desire to fill a suicide role than those with limited knowledge.

New arrivals had three types of fighting roles: conventional fighter, suicide bomber or suicide fighter, apparently meaning someone who takes part in high-risk raids with an increased likelihood of being killed.

The records contain indicators that Islamic State was using the forms to “talent scout” and identify individuals with specific skills or knowledge that might prove useful to the group in the future, the report found.

The authors suggest this showed the organisation was learning from its mistakes.

“In 2008 the Islamic State of Iraq, the precursor to the Islamic State, produced a document that analysed why it experienced setbacks in the 2006-07 timeframe in Iraq.

“One of the group’s findings identified the failure of certain emirs in the organisation to properly exploit the talents of their fighters, oftentimes tasking them with jobs that did not match their background and expertise,” it stated.

Employment history

A question on previous work shows the fighters included ex-policemen and soldiers as well as pilots, journalists, online marketers, IT workers and many students.

Recruits with unique skills, including a former technician at a petroleum plant and those with experience in aviation, were flagged by Islamic State officials as having potentially useful experience.

Not all occupations were seen as desirable, however. A 24-year-old from Gaziantep in Turkey was listed as having been a "drug and hashish dealer". His form contained a note from an Islamic State official stating: "May God forgive him and us!"