The Internet has become a new domain for conflicts between the Republic of China (Taiwan) and the People’s Republic of China (China) with their complicated history. China’s cyber warfare against Taiwan is diverse and comprehensive. To defend Taiwan’s democracy, it has embraced a top-down approach in shaping its cybersecurity policy. Specifically, Congress amended the National Security Law to extend Taiwan’s territory to the Internet. This mirrors the notion of “Internet Sovereignty,” a principle endorsed by China’s Internet governance regime, diverging from the principle of a free and open Internet.  Taiwan’s endurance of China’s attacks captures the two metaphorical views of the Internet, steering the course of normative development within the realm of Internet governance. Much of the foundational engineering of the Internet is embedded in the “cyberspace” metaphor, specifically evident in the United States (US). This has driven early discussions in the United Nations (UN) on developing cyber norms, which entails voluntary expectations of responsible state behavior. Simultaneously, China has been consistently advocating for the metaphor of “Internet Sovereignty” and has constructed its narrative through the Shanghai Cooperation Organization (SCO), its Cybersecurity Act and the Digital Silk Road (DSR). Countries are encouraged to maintain control of information flows in a given territorial realm. To uphold Taiwan’s democratic system, this research argues that Taiwan should embrace the metaphorical view of the Internet as “commons,” transcending conceptions of “cyberspace” or “sovereignty.” This research further classifies the Internet commons from three dimensions: “cable commons,” “communications commons,” and “content commons.” Each commons presents its unique set of challenges. The tragedy of each commons, like cable interception, cyberattacks, and the dissemination of disinformation, introduces scenarios akin to cases of overexploitation. These situations give rise to the collective action problem reminiscent of classic social dilemmas – a “tragedy of the commons.” Developed by Nobel Laureate Elinor Ostrom, polycentric governance offers a solution for the tragedy of the commons by facilitating coordination among diverse actors. It fosters norm development by adeptly tackling collective action problems through coordinating and harmonizing diverse decision making centers in the Internet. This offers a strategic advantage for Taiwan to safeguard its democratic system from the bottom-up in the various Internet commons.