China is systematically building a legal framework for a potential invasion of Taiwan. How can Taiwan’s friends, partners, and allies push back?
We come together as a unique writing team: military lawyers from the U.S. and Taiwanese armed forces. We seek here to explore China’s ongoing legal preparations for the use of force against Taiwan and uncover likely legal maneuvers Beijing will employ in the lead-up to an invasion. On that basis, we outline key steps for Taiwan’s international supporters to strengthen deterrence, including dismantling China’s legal pretext for aggression and implementing coordinated counter-lawfare strategies to challenge Beijing’s lawfare campaign.
Why Does a Legal Framework for War Matter?
Legal frameworks shape the way conflicts are justified, perceived, and responded to — both domestically and internationally. By crafting a legal basis for war, China is not only preparing its domestic landscape for a Taiwan invasion but also seeking to influence global narratives, erode Taiwan’s international support, and reduce the likelihood of foreign intervention.
Beijing understands that modern warfare extends to the legal domain, where the struggle for perceived legitimacy is paramount. By embedding this mindset into its military strategy, China aims to frame an invasion as a lawful internal matter, fostering diplomatic ambiguity that could deter international opposition and delay collective security responses. This is particularly critical in an era where legitimacy plays a central role in shaping geopolitical alignments and the willingness of nations to take decisive action. Through legal instruments like the Anti-Secession Law, Beijing is setting conditions for the use of force by normalizing its legal claims, asserting jurisdictional control, and criminalizing resistance. This incremental approach to lawfare seeks to shift the strategic environment in China’s favor before conflict, making an eventual invasion seem like a reasonable and legally justified course of action.
Countering China’s legal preparations for war is therefore essential to preserving peace and security in the Western Pacific and ensuring that international law remains a bulwark against aggression, rather than a weapon used to facilitate it. The more China’s lawfare is exposed and opposed, the harder it becomes for Beijing to legitimize aggression against Taiwan, both at home and abroad.
China’s Legal Case for Taking Taiwan
China leverages its “one China principle” as a purported legal justification for a Taiwan invasion, labeling the issue an “internal matter” exempt from the U.N. Charter’s prohibition on the use of force. Amid rising geopolitical tensions over the past two decades, Beijing has intensified efforts to promote its one China principle internationally. Simultaneously, Beijing has institutionalized its one China principle domestically by establishing a legislative framework rooted in its 1982 constitution, which designates Taiwan as an inseparable part of the People’s Republic of China.
In 2005, after Taiwan reelected a president viewed by Beijing as pro-independence, China enacted the Anti-Secession Law to signal its resolve and willingness to use force. Notably, the law mandates “non-peaceful means” if Beijing identifies undefined “major incidents” entailing secession, or deems peaceful “reunification” unachievable. Since its enactment, the Anti-Secession Law has become a cornerstone of Beijing’s lawfare campaign against Taiwan, providing a domestic pretext for escalating coercion and military threats.
Throughout the 2000s, as Taiwan sought to deepen ties with democratic partners and expand its global presence, China reinforced the Anti-Secession Law with additional domestic laws that framed foreign engagement with Taiwan as a violation of its sovereignty. Among these, the National Security Law (2015) and National Defense Law (2020) authorize military action to defend China’s claimed territory, incorporating Taiwan-related preparations into a broader national security structure aligned with Xi Jinping’s push for modernization of the People’s Liberation Army (hereafter, Chinese military) and centralized war powers.
By 2021, as U.S. and allied naval operations increased in the Western Pacific, China enacted the Coast Guard Law and Maritime Traffic Safety Law, granting its maritime forces sweeping authority to regulate and control so-called jurisdictional waters. In Beijing’s view, this includes not only Taiwan’s territorial sea but also areas of the Taiwan Strait where international law guarantees high-seas freedoms to all nations. A series of maritime notices and coast guard regulations have since expanded domestic enforcement powers even further, enabling Chinese authorities to exclude, detain, and use force against foreign vessels. Meanwhile, in the airspace above the Taiwan Strait, China implemented modified civilian flight routes, creating opportunities for military aircraft to blend with civilian air traffic and strain Taiwan’s air defenses. Together, these legal maneuvers strengthen the Chinese military’s counter-intervention strategy by masking potential cross-Strait aggression within routine activity, buying time and space to amass forces for conflict without foreign interference.
Building on this foundation, China has adopted an increasingly aggressive and sustained posture in the Taiwan Strait, catalyzed by perceived provocations — most notably, former U.S. Speaker of the House Nancy Pelosi’s 2022 visit to Taiwan. Since then, China has worked to normalize large-scale joint operations, routine centerline crossings, and persistent air and naval patrols near, and sometimes within, Taiwan’s claimed territorial sea and airspace. This pattern reached new heights with last year’s Joint Sword exercises, featuring unprecedented blockade and invasion rehearsals staged in response to Taiwan’s election of President William Lai, whom Beijing labels a separatist. Joint Sword also showcased Beijing’s military-civil fusion strategy, with the Chinese military integrating commercial roll-on/roll-off ferries in amphibious formations — intentionally blurring the legal distinction between civilian and military objects to obscure aggression and complicate decision-making by law-abiding adversaries.
Consistent with its military-civil fusion strategy, Beijing’s recent institutional reforms under the National Defense Mobilization Act (2010), Cybersecurity Law (2017), and National Defense Transportation Law (2017) support rapid force expansion during conflict by ensuring military access to dual-use technologies and infrastructure, such as commercial shipping, civil aviation, and artificial intelligence. The National Intelligence Law (2018) reinforces this approach by compelling Chinese companies and foreign firms to assist in intelligence gathering, potentially weaponizing foreign data against Taiwan’s supporters. Reports of newly developed, purpose-built landing barges reflect emerging dual-use threats on the front lines, as the Chinese military harnesses whole-of-society power to enhance critical capabilities for an invasion.
In addition to conventional force rehearsals during Joint Sword, Beijing seized on Lai’s election to escalate its lawfare campaign. Shortly after his inauguration, Beijing introduced 22 new rules to bolster enforcement of the Anti-Secession Law, criminalizing support for Taiwan independence and expanding its authority to prosecute alleged “separatists.” These measures, which allow trials in absentia and, in some cases, the death penalty, signal an intensified effort to pressure Taiwan’s leaders, businesses, and civil society into submission.
By strengthening its legal foundation for invasion, Beijing aims to achieve what the Chinese military’s “three warfares” strategy calls “legal principle superiority” — a position of strategic dominance intended to legitimize escalating coercion and potential aggression. A recent Lowy Institute report highlights progress toward this goal, revealing that nearly half of U.N. member states now endorse Beijing’s one China principle and all efforts toward unification. Crucially, this support comes without explicit conditions for peaceful resolution, arguably signaling tacit consent for Chinese military aggression. Indeed, Beijing’s strategic use of lawfare appears to be gaining ground in preparing both the legal and physical environments for potential conflict.
