Europe's Quagmire: Homecoming Terrorists and 'Lone Wolves' to Plot and Kill

"Daesh has raised its ambitions," Lari Nyroos, chief analyst at the Swedish Security Service's department for counterterrorism, told Expressen. According to him, security services across Europe are now poised with a problem of numerous approaches to terrorist attacks, from the simplest to the most complex.

Last year, Daesh managed to carry out 60 attacks in a dozen countries outside the war zones in Syria and Iraq, he noted, citing various attack patterns, ranging from single actions to craftily masterminded operations.

According to Nyroos, home-bred European radicals who fail to to get to Syria or Iraq may instead shift to preparing attacks on the home turf or support terrorist activities otherwise.

At present, Daesh's elite soldier Osama Krayem from Malmö is imprisoned in Belgium suspected of being an accomplice to the terrorist cell behind the bloody attacks in Paris and Brussels, whereas the teacher college drop-out Sevigin Aydin is charged in Stockholm for preparing a lone suicide attack against targets in Sweden. Remarkably, Aydin was reported to have watched a YouTube-clip where Daesh spokesman Abu Muhammad al-Adnin addresses lonely sympathizers abroad at least 18 times, whereupon he downloaded a bomb manual from the web and got down to business.

"The fact that propaganda is so easily accessible, leads to 'lone wolves' being quickly "self-radicalized" and trained with the intent to commit acts of terrorism without even having any physical contact or communication with people linked to a terrorist group," Lari Nyroos said, citing Daesh's appeal from 2014 to the group's sympathizers to take single action.

Earlier this week, the very same Expressen tabloid revealed that the Security Service was investigating a tip-off from the Iraqi security service about a cell with seven to eight experienced Daesh terrorists, who may have infiltrated Sweden.

"It is all about creating lengthy, complex operations involving firearms, which result in a super drama that paralyzes an entire city and creates a huge polarization," terrorism expert Magnus Ranstorp of the Swedish National Defense College said.

The Iraqi ambassador in Stockholm believes such an attack actually would not be anything strange.

"Many people went to the war in the Middle East and now they are coming back to Sweden," Ambassador Baker Fattah Hussen told Expressen. According to him, this is nothing peculiar to Sweden alone, as the returnees are flooding the whole of Europe.