Jus in bello, also known as the law of war, the law of armed conflict (LoAC) or international humanitarian law (IHL) is the section of international law dealing with the protection of persons who are not or are no longer participating in the hostilities and restricts the means and methods of warfare. It comprises of treaty law and of customary law, as the latter has been crystallised throughout history.

Treaty law consists mainly of two sets of treaties: the so-called Geneva and Hague law.

The first one, Geneva law concentrates on the protection of civilians, prisoners of war, wounded and sick on land and at sea, comprising of the four 1949 Geneva Conventions (supplementing earlier Conventions of 1846, 1906 and 1929). It is further complemented by the two Additional Protocols of 1977, relating to the protection of victims of international and non-international armed conflicts. Additional Protocol III was added in 2005 relating to the Adoption of an Additional Distinctive Emblem.

The second one, Hague law deals with practical military aspects of the conduct of hostilities, consisting of the Hague Regulations of 1899 and 1907, coupled with various other conventions and agreements prohibiting the use of certain weapons and military tactics.

This section will deal with the possible application of the law of war in international cyber conflicts, and more particularly, with the application of the general principles of LoAC in cyber attacks, since the law of war must apply to all military operations and cyber warfare operations should not constitute an exception.

However, can IHL be applied to information warfare operations?

Various authors take for granted that cyber conflicts are indeed subject to humanitarian law, without questioning the applicability.

It needs to be established that the ‘rules of international law applicable to any armed conflict’ and that the Geneva Conventions which are applied ‘to all cases of declared war or of any other armed conflict which may arise between two or more of the High Contracting Parties’ are also valid for cyber warfare operations.

So, does a cyber conflict equate an armed one?

Departing from the jus ad bellum analysis of this paper, regarding an ‘armed attack’, it has to be mentioned that the only definition of an ‘attack’ in IHL is in AP I article 49, which defines an ‘attack’ as ‘acts of violence against the adversary, whether in offence or in defence’. Consequently, cyber attacks definitely fall within the ambit of this definition.

After all, the accepted as customary law AP I article 36 declares that ‘in the study, development, acquisition or adoption of a new weapon, means or method of warfare, a High Contracting Party is under an obligation to determine whether its employment would, in some or all circumstances, be prohibited by this Protocol or by any other rule of international law applicable to the High Contracting Party.’