The first edition of this Egmont Paper was released exactly one year ago. Its aim was to explore the wider context that could help explain the decision of thousands of mostly young European volunteers to journey to a faraway war theatre in the Levant. This Egmont Paper is a thoroughly revised, updated and expanded version. Several new features have been introduced. It proposes, firstly, a more systematic attempt at understanding why people with different social backgrounds feel attracted by Islamic State (IS). Two categories of Syria travellers (a more general term than ‘foreign fighters’) can be identified. The first group comprises pre-existing kinship and friendship gangs. For them, joining IS is merely a shift to another form of deviant behaviour, next to membership of street gangs, rioting, drug trafficking and juvenile delinquency. But it adds a thrilling, larger-than-life dimension to their way of life – transforming them from delinquents without a future into mujahedeen with a cause.