This research explores the perspectives of academic physicists from three national contexts concerning their roles and responsibilities within the realm of science. Using a dataset comprised of 211 interviews with scientists working in China, the United States, and the United Kingdom, the study seeks to explain whether and in what manner physicists conceptualize scientific ethics within a global or national framework. The empirical findings bring to light disparities across nations in the physicists' perceptions of what constitutes responsible mentorship and engagement in public service. These cross-national variations underscore the moral agency of physicists as they navigate the ethical standards embraced by the global scientific community vis-a-vis those that are specific to their respective national contexts. The study's empirical insights may carry significant implications for both policymakers and ethicists, underscoring the imperative of soliciting and acknowledging the perspectives of academic scientists working and living in disparate national contexts when formulating comprehensive science ethics frameworks. Such inclusive and context-aware approaches to shaping ethics in science can contribute to the cultivation of a more robust and universally relevant ethical foundation for the scientific community.