Not too long after the Paris terrorist attacks of 13 November 2015, French president Francois Hollande declared ‘war’ on Islamic State (IS), which was held accountable for the carnage. Other leaders, like Dutch prime minister Mark Rutte did as well. Whether declaring war was an emotional response to a dramatic event or a calculated way to avoid domestic polarization over the perceived threat posed by (Muslim) immigrants by pointing towards an external enemy, it does have serious implications.

First of all, ‘war’ is an activity described and limited by international law. Simply put, it is an announced violent exchange between two states. So, if ‘war’ can only occur between state actors, does that mean that IS is a state actor? If so, it would mean the implicit recognition of IS as such by an international community it intents to abolish. World leaders thus far have shown no intent of recognizing IS as a state actor; the United States keeps referring to IS as Islamic State in Iraq and Levant, only to emphasize that it officially does not have a territory of its own, but rather is active within the border of two state actors that are recognized.

Second, if several countries – like France – are at ‘war’ with IS, how should the events of 13 November be labeled then? Instead of ‘acts of terrorism’ these would be ‘acts of war’. This distinction was already made explicit in 2014 by American Secretary of State John Kerry, who then did not speak of ‘war’ against IS. Although acts of war might still be regarded terror attacks – think for example to the militarily unnecessary bombing of the German city of Dresden during the Second World War –, the Paris attacks might formally be considered war crimes. Viewing the attacks as acts of war suggests an approach that seems to legitimize them by moving away from the internationally totally unacceptable acts of terrorism.

In line with the second implication, a third would be that captured perpetrators of the Paris attacks would not be terrorists, but prisoners-of-war. Prisoners-of-war fall under the Geneva conventions, which secure their rights. One of the rights is to be part of prisoners’ exchanges between the warring parties. Apart from world leaders probably being not too eager to support such exchanges, a consequence might be more kidnappings by IS simply because IS needs prisoners to exchange.

The implications mentioned above of declaring ‘war’ on IS are farther-reaching than might be intended by the Western leaders. Although understandable given the extreme situation, use of the word ‘war’ – with all its consequences – should be limited to those conditions when actually appropriate: hostilities between state actors.