title: Collective Countermeasures in Cyberspace – Lex Lata, Progressive Development or a Bad Idea?
abstract: This paper analyses whether international law permits collective countermeasures against states responsible for cyberattacks. In her opening address at CyCon 2019, Estonia’s President Kersti Kaljulaid presented Estonia’s view that ‘States which are not directly injured may apply countermeasures to support the state directly affected by the malicious cyber operation’. This view was rejected by France in its declaration of 9 September 2019 on how international law applies to cyber operations. Disc