PARIS — European nations are bracing themselves for the return of their citizens who had left to fight the wars in Syria and Iraq.

"The EU member states most affected expect a slow but gradual rise of returnees," noted a recent Radicalization Awareness Network (RAN) report submitted to the European Commissioner for Security, Julian King.

The return of men, women, and children who left the Old Continent to take part in the war in Syria and Iraq is particularly a problem for France. It was here that a European citizen, Abdelhamid Abaaoud, among other terrorists, struck Paris on Nov. 13, 2015. And although security forces ended up killing Abaaoud, there are many like him who continue to haunt European governments.

The problem isn't specific to France. The RAN report also focuses on Germany, Spain, Italy, Britain, Belgium, the Netherlands, Austria as well as Scandinavian countries.

The return of jihadists to their countries of origin is, in itself, nothing new, but the growing number of said jihadists is remarkable. According to the latest estimates from the U.S. Senate Committee on Homeland Security, quoted in the report, more than 42,000 "foreign terrorist fighters' (FTF) from more than 120 countries have joined the ranks of ISIS in Iraq and Syria in just five years — between 2011 and 2016. That's far higher than the sum total of people who have joined jihadist organizations in the past three decades put together.

A study by the Swedish Defense University, also noted in RAN's report, lays out the figures for previous jihad campaigns: Afghanistan (about 20,000 foreign volunteers between 1980 and the 1990s), Bosnia (some 2,000 foreign jihadists between 1992 and 1995), Chechnya (a few hundred, often from the Arab world, in the 1990s and the 2000s) and Iraq (about 5,000 in the mid 2000s).

Among the foreign fighters in Syria and Iraq, "more than 5,000 have come from Europe," according to the report. European intelligence services believe that 1,200 to 3,000 of them might return, with many women and children among them. Until this summer, an estimated 30% of FTFs have returned to Europe, although RAN says that the figure for Denmark, Sweden, and the United Kingdom is closer to 50%.

Experts see two "generations' of FTFs here: The first generation, who has already returned, "was predominantly men, and comprised those who had been motivated to leave for humanitarian reasons and/or fighting the Assad regime — with some notable exceptions —, more prone to disillusionment, arguably less violent and relatively free to leave the terrorist-held territory," the report says.

The "new" FTFs are "more hard-wired in their beliefs, and trained in how to act and respond to (formal and informal) questioning" from special services.

The second generation, however, comprises fighters currently returning. They are "more battle-hardened and ideologically committed, had to evade pervasive surveillance by Daesh the Arab acronym for ISIS to escape and may have come back with violent motives: to harm EU citizens." In other words, police officers and magistrates interviewed by RAN claim that, contrary to those who returned "in the earlier days' of ISIS, the "new" FTFs are "more hard-wired in their beliefs, and trained in how to act and respond to (formal and informal) questioning" from special services.

The report underlines that, in addition to the Nov. 13, 2015, attacks in Paris, the plots that targeted Brussels in March 2016 were also committed by FTFs. "While many FTF returnees will not become operational terrorists," the report says, "mere contact with "jihadi" terrorist groups ... translates into significant national security risks." It is therefore crucial to precisely identify them so as to better assess the level of danger they pose and to accordingly "tailor" responses.

Disillusionment and remorse

RAN also noted several motives for FTFs who want to return to their country of origin: disillusionment and remorse due to the "dire living conditions', "a loss of power from terrorist group they belonged to", family pressure and intervention, poor health due to injury or childbirth, a desire to return after taking refuge in Turkey, and, disturbingly, the intention to carry out an attack.

For the Dutch foreign intelligence agency AIVD, beyond the question of what "motivates' FTFs to return, the duration of their stay in Syria or Iraq and their activities there are equally important in order to "assess' an individual.

The risk FTFs represent is not limited to the attacks they might potentially commit. RAN notes that even if they're "not engaged in criminal behavior", they "may still strongly support ideologies opposing apostates, other religions, so-called infidels, women's rights and even EU society." The spread of this ideology has many European officials worried.