Fears of Islamic State (IS) “sleeper cells” infiltrating Europe on the back of the recent refugee exodus and creating anything from lone-wolf to 9/11 style attacks have been highlighted in recent weeks by the media, conservative politicians and far-right groups.

Although there have, indeed, been calls by the IS for sleeper-cell attacks following the United States-led coalition airstrikes on IS-held territory, hard evidence of an organised attempt to plant cells within the refugee exodus is hard to come by.

Unpicking the actual facts behind a scattered melange of rumour and scaremongering is even more challenging.

Far more worrying, few appear focused on what this all means for Europe over the longer term.

… Dr Shashi Jayakumar is Senior Fellow and Head, Centre of Excellence for National Security at the S. Rajaratnam School of International Studies.