Question

Historically, customary international law (CIL)—rules derived from consistent state practice arising from a sense of legal obligation (*opinio juris*)—served as the primary regulatory framework of international relations. By the late twentieth century, however, the proliferation of multilateral treaties established a positivist paradigm that relegated CIL to a secondary role, viewing explicit sovereign consent as the only legitimate source of binding international norms. Recently, a contingent of legal theorists has advocated for a resurgence of CIL to govern domains characterized by rapid technological advancement, such as cyber warfare. These theorists argue that the glacial pace of treaty negotiation renders treaties obsolete in regulating cyberspace, whereas CIL can organically evolve alongside state practice. However, this advocacy fundamentally misapprehends the mechanics of *opinio juris*. The formation of CIL requires that state actions be motivated by a shared recognition of legal duty. In the realm of cyber warfare, state practices—such as the deployment of zero-day exploits or the maintenance of strategic ambiguity—are almost exclusively dictated by classified, unilateral security imperatives and realpolitik, rather than any emerging normative commitments. Consequently, any attempt to derive a modern regulatory framework for cyber warfare primarily by observing current state practices...

Which of the following most logically completes the passage?