Recruitment across the three countries appears to have peaked in 2013 and 2014 when ISIS was aggressively expanding throughout Iraq and Syria.
Around 90 Norwegians have gone abroad to join up with Isis and the Norwegian intelligence service PST believes that at the end of 2015 there were still roughly 40 Norwegian foreign fighters actively participating in hostilities in Syria and Iraq.
Magnus Ranstorp, Research Director Center for Asymmetric Threat Studies (CATS)at the Swedish National Defence College, believes that this partially has to do with the fact that Isis has already attracted many of the disaffected citizens in these countries who were receptive to the organisation's extremist ideology.
“One of the explanations is that at the start of the conflict, Isis recruited many of the so-called ‘low-hanging fruits' – in other words: The easy recruits. These are people who may have been unemployed or involved in crime,” Ranstorp told Ritzau.
Ranstorp believes that the state of the on-going conflict also helps explain the decline in new Isis recruits from the Nordic countries, however.
“People have increasingly begun to realise just how brutal this war is. And there are reports that Isis are also operating under more difficult conditions,” he explained.
PST also expects a further decline in the number of Norwegian citizens leaving to join the war in Syria in 2016.
“Military operations against Isis are deterring new recruits and leading to a higher number of foreign fighters being killed,” a recent PST report noted.