This article considers the implications of criminalised Muslim Diaspora community members from the West travelling to the Middle East and becoming involved in the terrorist activities of the Islamic State (IS), and ultimately returning from whence they came. It also reflects on the differences over time amongst the profile of recruits that have taken place since the time of the Mujahedeen in Afghanistan, to the ascendancy of IS. Recent research indicates both terrorist and organised crime groups draw recruits from the same Diaspora communities, a position supported in this article. While the focus of law enforcement and media attention appears to be on the potential of Islamic State Middle East veterans committing terrorist acts in the West on returning from conflict zones, there may well be a pervasive danger of them bringing significant risk to their countries of origin through enhanced participation in organised crime. The views of a selection of recently retired police professionals were gathered, and were found to support concerns around this potential significant and dangerous outcome of homecoming foreign fighters.