The action alone does not provide much evidence to lean towards either natural terrorism or state induced terrorism. None the less, there should always be questions as to how a state might benefit from terrorism, as terrorism is usually a consequence of a state.
As for how a state might induce this sort of terrorism, it is rather simple. It is some combination of indirection, religion, and incentive. In the most simple form, an agent of the state pays someone to commit terror. It a less simple form, a state subtly controls a religious organization, or faction, which encourages extremist groups on the basis of religion, and provides incentives, through indirect paths, to terrorists for committing terror.
For a state to do this in another state’s territory, it must have a very good intelligence network, or else there is some likelihood the state support will be found out, and it will be considered an act of war. This tends to limit the potential state backers to: the native country, the US, France, Turkey (regionally), Britain, Russia. (There are some additions depending on the location).
What would the state of France have to gain by further terrorism? Well, to answer this, it is necessary to understand what is going on in the middle east, specifically Syria and Iran. This is quite a large subject, so I will just gloss over it here, since it is not the topic of this article: The “arab spring” was artificial, spawned by the US and Britain to remove various powers for various reasons. The Syrian debacle, presented as a civilian rebellion, was nothing more than US, Saudi Arabia, Turkey, France, and Britain attempting to overthrow the government of Syria. The series of destabilizations and overthrows, starting with Tunisia, ended in Syria with the help of Russia and Iran, and a very resilient Syrian government.
So, back to the question of what would France have to gain by further terrorism? In the past, it has been the excuse to bomb Syria in an effort to destroy Syria’s government’s control under the guise of fighting ISIS. It could still be this is the reason, but there are other issues to consider.
The consequence of letting in supposed ‘refugees’ of an inherently violent religion were known in the outset, but are now being understood by the general population of the countries of Europe. So, whenever there is a terrorist event by someone of this religion, or by a refugee, the general populace of Europe becomes more inclined to desire shutting their borders. And, an open border to refugees being the policy of the EU, terrorist events destabilize the EU. And, from this, we can see this event could also be either a member state in the EU wanting to leave the EU, and sponsoring terrorism to sway the populace of the state towards leaving the EU, or it could be Russia, with the desire to break up the EU, (the EU which has mostly acted against Russian interests), or, it could even be Turkey, with the idea of getting France, and other countries, to continue its efforts towards overthrowing the Syrian government.
There are even further considerations in regards to US and British interests in the euro and European banks that provide a motive, but this avenue of thought becomes convoluted quickly.
There is also a general method of using terrorism as a distraction from something else more important, but I’ve rarely seen this as the only reason – it is usually combined with multiple.
Now, frankly, I haven’t been keeping up with middle east power plays, so I could be missing something entirely or I could be off the mark.
The problem with this sort of religious group is terrorism can be either natural or artificial. It is a matter of determining whether a snake bite was induced or just a consequence of proximity and the nature of the snake.