Is the Swedish Territorial Defence Ordinance applicable on the fourth arena?

Like other modern societies, Sweden is highly dependent on its digital infrastructure in order to run vital functions such as electricity, water purification, information and communications. Even though this infrastructure is characterized by transboundary features, it is clearly a part of the Swedish state. In peacetime, the Swedish armed forces are tasked to protect and defend the geographic territory of the state from violations, and the authority to do so is given by the Territorial Defence Ordinance. However, according to the analysis of this paper, the ordinance can not be applied on the digital parts of the society, by the military called “the fourth arena”. Numerous difficulties rises with an application of the ordinance in its present wording and against this background, it is of interest to clarify the present legal situation and suggest a way forward in order to achieve adequate protection on the same premises as the other arenas. The interdependency between national and international law on this matter is pointed out and international law is used to interpret the national ordinance. The conclusion is that the Swedish politicians and legislators´ needs to find legal support for the defence of the Swedish digital interests and infrastructure by seeking cooperation and legislative solutions in an international context and by doing so, hopefully the national legislation will follow. The legal challenges faced by Sweden are likely to be similar in several comparable countries, why this discussion should be of interest for other states and held in an international context.