Research on the Interpretation of Customary International Law in Cyberspace: Dilemmas and Solutions

In recent years, the international community has reached a preliminary consensus on the application of customary international law (CIL) to cyberspace. However, discussions have now entered the deep waters of interpreting specific rules regarding how it applies. Traditionally, the interpretation of CIL is primarily divided into two methods: induction and deduction. Concerning the two constitutive elements of CIL—state practice and opinio juris—the inductive method requires a high degree of consistency in state practice. In cyberspace, inconsistency in state practice is prominent. Strict adherence to induction would make it difficult to genuinely form a CIL norm. The deductive method can relax this requirement, but due to the lack of specific standards regarding the permissible extent of deduction, it is highly susceptible to the adverse influence of power politics in cyberspace, potentially leading to the "hollowing out" of CIL norms. At this juncture, introducing John Rawls' "reflective equilibrium" to interpret the constitutive elements of CIL in cyberspace can address the shortcomings of both deduction and induction. Their combination can provide an analytical tool balancing stability and flexibility for interpreting CIL's constitutive elements, thereby promoting the shift of CIL in cyberspace from "hollowing out" to "substantialization."