Asymmetries in the international regulation of sensitive technologies reflect structural inequalities between regulatory regimes. This article investigates the factors that explain the different regulatory outcomes of nuclear and cyber technologies, questioning why one has achieved high institutionalization while the other remains fragmented. The objective is to compare the regulatory trajectories of these two strategic regimes using the norm lifecycle model, identifying the elements that favor or hinder the consolidation of international norms. The methodology consists of a structured comparison, based on binary coding of variables specific to each stage of the normative cycle (emergence, cascade, and internalization), applied to an analytical matrix constructed from specialized literature and relevant institutional documents. The results indicate that the nuclear regime presents a high normative density in all phases, with consolidated institutional frameworks and strong internalization, while the cyber regime suffers from institutional gaps, epistemological fragmentation, and the absence of binding instruments. It is concluded that the observed differences arise from the combination of institutional legacy, techno-scientific consensus and enforcement capacity, factors that explain the normative asymmetries and offer analytical support for understanding the regulation of other emerging technological domains.