Trade and investment relations between Taiwan and China have been more noticeable for their impacts on Taiwan than on China in both economic and security terms. Instead of discussing the political and military consequences of this asymmetrical economic interdependence, this paper suggests an analytical framework for exploring the effects of the externalities of cross-Strait market forces on Taiwan's security from a nontraditional security perspective. Economic factors, independent from traditional security notions, are vital to Taiwan's international survival and domestic stability. Vulnerabilities and concerns arising from cross-Strait de facto economic networks are the externalities to the basic source of Taiwan's international expansion, leverage over the geoeconomic order, and the state's capacity to manage internal cohesion. In conclusion, the transnational nature of nontraditional security issues and the relevance of cross-Strait economic ties to China's economic security suggest the possibility of more interest-based responses to the identified concerns.