Last November’s summit between U.S. President Joe Biden and Chinese President Xi Jinping in Woodside, California, was hailed as a harbinger of progress in stabilizing a superpower relationship that was spiraling toward conflict. Yet more than eight months later, it’s evident that leader-to-leader engagement merely extended the illusion of constructive bilateral engagement—reinforcing, rather than reversing, the declining trend lines in the U.S.-China relationship.

Indeed, the principal paradox of the Biden administration’s China policy lies in its unintended consequences. Far from mitigating Beijing’s brashness, Washington’s diplomatic overtures have instead emboldened Xi, who appears not merely disinterested in stabilizing relations but actively working to undermine them. Left unchecked, further accommodating Beijing’s aggression today could lead to Chinese overreach tomorrow, raising the specter of miscalculation—or worse, war.

Nowhere is this dynamic clearer than in the South China Sea, where Washington and Beijing are careening toward a crisis.

The South China Sea has long been a flash point for territorial disputes. China, the Philippines, Vietnam, Malaysia, Brunei, and Taiwan all assert overlapping claims over this strategically significant and resource-rich region, through which an estimated $3.37 trillion in trade traverses annually. Many of these disputes date back to the mid-20th century. However, regional tensions have surged in recent years as China has aggressively expanded its territorial and maritime claims, frequently asserting “indisputable sovereignty” over all South China Sea islands and their adjacent waters.

A pivotal moment came in 2016, when the Permanent Court of Arbitration in The Hague, in a case brought by the Philippines, explicitly invalidated China’s claims over nearly 90 percent of the South China Sea. The tribunal—which adjudicates international disputes, including those arising from the United Nations Convention on the Law of the Sea—also noted that China had “violated the Philippines’ sovereign rights” by illegally operating in its exclusive economic zone (EEZ) and interfering with Philippine petroleum exploration. But instead of accepting the ruling, Beijing rejected it outright. Over the Obama administration’s objections, Beijing subsequently built and militarized several artificial islands throughout the South China Sea, including Mischief Reef and Fiery Cross Reef within the Philippines’s internationally recognized waters, greatly heightening regional anxieties.

Fast-forward to today, and long-simmering tensions have sparked repeated clashes between the China Coast Guard and the Philippine military. The most notable area of contention is around Second Thomas Shoal, a disputed reef located in the Philippines’s EEZ but claimed by China. Since last December, Chinese vessels have repeatedly fired water cannons at Philippine ships seeking to resupply a remote, rusting outpost located at the shoal. Chinese forces have also rammed Philippine ships to prevent them from completing their resupply missions, which occur every four to five weeks.

Last month, China Coast Guard crews upped the ante by boarding a Philippine resupply vessel and threatening sailors with swords, resulting in severe injuries, including the severing of a sailor’s thumb. Following the incident, Chinese ships forcibly towed Philippine vessels away from Second Thomas Shoal. Manila has since vowed to defend its sailors with the “same level of force” should Chinese crews assault them again. A clash of this nature could prompt Manila to invoke its 1951 Mutual Defense Treaty with Washington, which obligates each country to defend the other in the event of an “armed attack” by an aggressor nation. Should that occur, the United States could find itself quickly drawn into a direct confrontation with China.

Further complicating the situation are rising maritime tensions in the Taiwan Strait—another area China claims in its entirety. This month, the China Coast Guard detained a Taiwanese fishing boat it says was operating in Chinese waters near the Kinmen Islands, which are governed by Taiwan but located just six miles from China’s coast. The incident led to a standoff between China’s and Taiwan’s coast guards, resulting in China seizing the boat and its crew. Days later, China dispatched 30 warplanes and nine naval vessels to encircle and intimidate Taiwan. Shortly after, Beijing escalated the situation further by sending 66 aircraft to encircle the island, with most of them blatantly violating Taiwanese airspace and tying the highest number of such violations ever recorded.

These and other recent risky rendezvous are not occurring in isolation. Instead, they comprise part of Beijing’s brand of regional revisionism, which aims to cement China’s control over the South China Sea by persistently and provocatively pressuring its neighbors in ways just short of open conflict. But beyond relying on brute force to assert its claims, China is increasingly leveraging its domestic laws to justify actions that clearly violate international norms, a tactic known as “lawfare.” In establishing an ostensible legal basis for its illegal maritime maneuvers, backed by its massive military buildup, China stands to both waive the rules and rule the waves—confounding its neighbors and forever altering the status quo in the South China Sea.

Beijing’s own legal rationale for its most recent activities can be found in a little-noticed provision of its 2021 Coast Guard Law known as Order No. 3. This directive, which came into full force in June, just two days before the latest incident with the Philippines, gives the China Coast Guard significant new authority to detain foreign vessels that enter China’s maritime “jurisdiction,” a likely reference to areas covered by China’s unilateral South China Sea claims. Adding to the uncertainty, the law also authorizes the use of force against vessels that “infringe on China’s national sovereignty,” without specifying what constitutes such an infringement. Such ambiguity fosters a climate of fear among China’s maritime neighbors, which must now weigh the risks of responding to China’s illegal incursions with the possibility that doing so could lead to war.

All told, Beijing’s evolving lawfare strategy underscores the urgent need to reestablish regional deterrence. Defending the Philippines, a U.S. treaty ally, is crucial not only for maintaining regional stability but also for reaffirming U.S. commitments to upholding other international norms and sovereignty claims. If the United States allows China to continue bullying the Philippines, other treaty allies such as Australia, Japan, and South Korea would rightly question Washington’s commitment to their defense. Such sentiments are already proliferating in many Southeast Asian nations—including Indonesia, Malaysia, Singapore, Thailand, and Vietnam—where polls suggest the United States is increasingly viewed as an unreliable security partner. Should these perceptions of U.S. weakness worsen, it could further embolden China. That makes it vitally important for Washington to take decisive action now, not later.

Despite repeated U.S. declarations of an “ironclad” commitment to the Philippines, China’s behavior remains unchanged. Beijing is betting that Washington, preoccupied with multiple global crises, will hesitate to fully honor its treaty obligations and attempt to dissuade Manila from risking a conflict over the shoal. This dangerous brinkmanship is designed to erode both U.S. resolve and Philippine resistance. Defusing tensions will require a counterintuitive approach: The United States must increase pressure on China and signal that further provocations will prompt a decisive and coordinated response. Such warnings must then be matched with credible actions to ensure their effectiveness.

One immediate deterrent would be for U.S. Coast Guard personnel to accompany Philippine sailors on so-called advise-and-assist missions to contested areas such as Second Thomas Shoal. Publicizing these missions would undoubtedly force China to reconsider aggressive action against Philippine vessels, knowing that an attack could prompt the United States to significantly escalate its involvement—a scenario Beijing is not yet ready to contend with and will likely seek to avoid. This approach would be far less provocative than deploying U.S. warships to escort resupply ships. If managed correctly, the presence of U.S. Coast Guard personnel could extend deterrence options while providing a buffer to de-escalate tensions, allowing for diplomatic offramps that could help China lower the stakes without losing face. Inviting Japan and other allies to participate in these missions could bolster regional security and demonstrate a unified stance against Beijing. Announcing new joint military exercises between the United States and its allies could further signal resolve to China and pressure it to course-correct.

Washington must also make a more concerted effort to mobilize international coalitions against Beijing, reaffirming core principles of freedom of navigation and territorial sovereignty. These issues should be raised in forums such as the United Nations Security Council, repeatedly if necessary. While concrete actions might be limited, such moves would force China to defend its actions on the global stage, potentially incurring reputational damage and rallying international support against its policies to change maritime borders by force. Recent statements from NATO leaders labeling China a “decisive enabler” of Russia’s illegal land grab in Ukraine highlight a growing international willingness to condemn authoritarian expansionism, underscoring that this issue extends beyond U.S.-China competition to a broader global context.

Lastly, while Washington has been overly cautious about sanctioning Chinese entities supporting Russia’s war machine, there exists substantial precedent for targeting China’s illegal maritime activities. Beyond targeted sanctions against Chinese personnel, U.S. policymakers should bolster existing sanctions on Chinese entities aiding in the buildup of China’s increasingly militarized Coast Guard. Working with allies, the focus should be on the China Shipbuilding Industry Corp. and China State Shipbuilding Corp., key players in constructing and maintaining Coast Guard vessels. Reinforcing technology export bans against these companies and their subsidiaries could also constrain the expansion and modernization of China’s maritime fleet over time.

Of course, reestablishing deterrence in the Pacific after years of accommodating Chinese aggression in the South China Sea and elsewhere will not be easy. But Washington must draw the right lessons from its failure to prevent Russia’s annexation of Ukrainian territory—namely that deterrence, once lost, all too often leads to war, a fate that must be avoided in Asia. Believing that this week’s provisional agreement between Manila and Beijing, which permits limited Philippine resupply missions to Second Thomas Shoal, will hold would be foolhardy. China has already made clear that the deal is temporary and that it will never accept a permanent Philippine presence on the shoal. Such signaling bolsters the case for strengthening deterrence to prevent future escalation—that is, before Beijing’s brinkmanship pushes the region into deeper conflict.