Responsibility for the attacks has been claimed by the Islamic State (IS), and Mr Hollande in a televised address has called it an "act of war" perpetrated by IS' "terrorist army". French authorities said one of the assailants who died at the Stade de France had been identified as Ismail Mostefai from a suburb of Paris, a man known as being involved in extremist ideology. The big question is: what does this mean for European involvement in the struggle against IS, and in the quagmire that is West Asia? Just a day earlier, dozens of members of the Shia community were killed by two ISIS-set bombs in Beirut, another city famed for its openness. The G-20 meeting in Turkey will unquestionably be overshadowed by this question. It is to be hoped that the right lessons will be learned by Europe from the United States' actions after 9/11. Leaders should seek to reassure an understandably scared population, and any response should be measured, with a clear aim and an exit strategy. Domestic lessons, too, must be learnt. The US, in addition, has certain advantages that allowed it to build up a far more pervasive security state after 9/11. Europe's leaders will hopefully be aware of the limitations of that strategy as a counter to such terrorist attacks. A more comprehensive solution must lie in preventing the further radicalisation of some in Europe's Muslim communities, not in creating states that push more deprived young men further down a path to fundamentalism and violence. Rebuilding the nationalist consciousness in a manner that can bring all sections of society into the national mainstream would be a goal worthy of pursuing.
At such moments it is futile to try and isolate which particular past foreign policy errors may have been part of the cause. France has run airstrikes against IS. But such arguments are even more purposeless when the details of IS' threats against France in the past year are examined; in July, the group released a video showing a French-speaking IS militant shooting a Syrian soldier, vowing to "fill the streets of Paris with bodies", and saying that IS "loved death like the French love life". It is unhelpful to sift through root causes when faced with such nihilism. But the world's response to IS - and surely there must be one now - must beware of responding with a nihilism of its own.