The Tallinn Manual and Jus ad bellum: Some Critical Notes

This essay critically analyzes certain aspects of “The Tallinn Manual on the International Law Applicable to Cyber Warfare”. It addresses specifically the Manual’s rules on the applicability of Jus ad bellum to cyber-attacks. The essay focuses on two particular aspects of this inquiry: the test or formula for classifying a cyber-attack as an “armed attack”, and the applicability of the right to self-defence to cyber-attacks by non-State actors. While drafters of the Manual present it as a humble lex lata project, the essay suggests that the Manual’s occasional deviation from the jurisprudence of the ICJ coupled with a possible lowering of the “armed attack” threshold, could lead to profound alterations of the landscape of future conflicts contrary to the declaration of its drafters.