Blurred description of legal authority—hard or soft law?
The nine new soft law instruments described in section 3 are referred to as manuals, guidance, papers, documents, and studies. Their names therefore indicate that they are of a non-binding character. However, there are major differences in how they describe their legal authority.
Three instruments clearly identify themselves—in their name and introductory section—as soft law instruments of a non-binding character, namely: the Montreux Document, which seeks to ‘provide guidance on a number of difficult and unclear practical and legal points’ (see section 3.4); the Copenhagen Guidelines and Principles, which seek to ‘develop principles to guide the implementation of existing obligations’ (see section 3.7); and The Lucens Guidelines for Protecting Schools and Universities from Military Use during Armed Conflict (see section 3.9).
On the other side of the spectrum, three instruments—those that the ICRC has been actively involved in preparing, the San Remo Manual on Armed Conflicts at Sea (see section 3.1), the study on Customary International Humanitarian Law (see section 3.2), and the Interpretative Guidance on the Notion of Direct Participation in Hostilities (see section 3.5)—claim to be straightforward expressions of customary international law or an authoritative ‘interpretation of IHL within existing legal parameters’ (see the Interpretive Guidance) and thus binding on all states as hard law. In this sense, it can be disputed whether they are ‘real’ soft law instruments. However, they have been included in this overview because a number of states have been unwilling to accept the identified rules as customary international law or as an interpretation of hard law standards. It is likely that these states would qualify the instruments as soft law instruments.
Finally, the last three instruments—the San Remo Manual on NonInternational Armed Conflict (see section 3.3), the Manual on Air and Missile Warfare (see section 3.6), and the Tallinn Manual on Cyber Warfare (see section 3.8)—are all described as non-binding soft law instruments, but at the same time it is claimed in the introductory paragraphs of the instruments that the identified rules in the manuals reflect (at least partially) lex lata, for example customary international law.
Hence, many of the guidelines and manuals seem to reflect a blurred mix of hard and soft law standards. Some instruments are clearly labelled as soft law instruments, but at the same time seek to gain authority from including hard law obligations; that is, customary international law.
Furthermore, even though a manual or guideline is clearly described as a nonbinding soft law document containing guiding principles, there is evidently a risk that the document will be used—or possibly misused—as evidence of customary IHL, as the UK Ministry of Defence tried to do with the Copenhagen Principles (see section 3.7).