In the realm of geopolitics, one major question that preoccupies scholars and policymakers alike is whether China will surpass or challenge US domination of the international system; crucial to this discussion is the role of China’s developing navy. However, when one looks at the history of continental great-power naval development (a process called hybridization), one sees different outcomes. What explains the variation in outcome of continental great-power hybridization, and what are the lessons for international politics? I argue that two factors explain where a continental great power’s attempt at hybridization will fall on the success-failure spectrum: investment persistence and threat diffusion. Investment persistence is the sustained financial support and political will to engage in naval development, despite perennial landward security challenges that threaten diversion of attention and resources to the army. Threat diffusion is the deployment of one’s navy to places or for purposes that do not antagonize the dominant naval power. When a continental great power engages in both investment persistence and threat diffusion, it is more likely to not only build a strong navy, but to be able to use that navy to execute policy objectives. Through archival and historiographical research of France, Germany, Imperial Russia, and the Soviet Union, I show how investment persistence and threat diffusion explain the varying degrees of success in continental great-power hybridization, and how such a combination could help China build a navy without irreparably damaging its relationship with the United States this century.