The last time France was struck by a terrorist attack was on October 1, 2017, when a man fatally stabbed two women outside Saint-Charles station in Marseille.
Despite the relative calm, the threat of terror has not been reduced on French territory. Official statistics released by the Interior Ministry showed that national security agencies have succeeded in thwarting 20 terrorist attacks last year alone and at least two in the first two months of 2018.
Authorities are not only concerned by sleeper terror cells or "lone wolf" terrorists, but they are primarily concerned by ISIS French recruits, who fought in Syria and Iraq and who are now returning home.
Even though many recruits were killed by airstrikes or in battles in Iraq and Syria since 2014, a significant number of them, enough to raise concerns for future French national security, remains.
The threat of returning fighters becomes stronger as ISIS incurs more defeats in Syria and Iraq.
Official figures estimated that no less than 1,700 Frenchmen or "residents" headed to Syria and Iraq starting in 2014.
At least 300 were killed, including 12 women. Some 256 have returned to French territory in various ways, along with 78 minors. Authorities estimate that some 730 people are still in conflict zones, with about 500 minors and children.
The threat posed by these returnees has French officials concerned. They see them as a serious security threat due to their experience in fighting in Syria and Iraq, radical ideology and knowledge on making bombs and explosives.
French President Emmanuel Macron and ministers of interior, foreign affairs and defense therefore reiterated the need to put to trial those who have been arrested in Syria and Iraq wherever they are.
This however has created a legal problem.
Most of the detainees have been arrested by Kurds (about 100 with Syrian Kurds and six families with Iraqi Kurds).
Neither Iraqi Kurds nor northeastern Syrian Kurds reside in countries with a recognized judicial system. Paris has however "turned a blind eye" to this legal dilemma because its security is at stake.
As for those held by the Iraqi judiciary, they raise a different security issue should some of them be sentenced to death.
Paris stressed that where a French citizen is sentenced to death, despite being a terrorist, French diplomacy will move to amend the sentence.
As for those who succeed in returning home, security services will hold them for questioning if they are an adult, whether a man or a woman, and refer them to the judiciary.
So far, a majority of returnees have either been sentenced to prison or subject to house arrest. They are forced to visit police stations periodically, while very few were released.