My dissertation—"Armed with good intentions? Explaining arms embargo compliance"—investigates why major arms exporters have come not only to comply with international arms embargoes, but also to embrace them as policy instruments. I examine and contrast the historical developments in two leading arms exporting nations, Germany and the United Kingdom. During the past 50 years, these countries moved away from treating arms embargoes as a nuisance they reluctantly navigated—and sometimes violated—to championing them as policy instruments. Based on rich case studies of the arms embargo regimes against South Africa and China, and interviews with policymakers and archival research, the dissertation finds that the growing strength of the arms embargo norm has made noncompliance a costly choice for arms exporting states.