Battleship: Power Moves in the Pacific
The South China Sea, courtesy of the International Crisis Group.
Introduction
Few stretches of water spark as much geopolitical tension as the South China Sea (SCS). Even the name for the region remains contested, reflecting the political tensions that surround it. Enclosed by various governments, the waters form the maritime crossroads of the Indo-Pacific. Nearly one-third of global shipping, comprising trillions of dollars in annual trade, flows through these waters, which binds the region’s economics to the SCS’s geopolitical stability. For states that depend heavily on these routes, such as Japan, China, the Philippines, Australia, the United States, and much of Southeast Asia, the stability of the SCS is essential to their economic and security interests.
Beyond its economic importance, the SCS is shaped by conflicting territorial claims that sharpen regional tensions. China, which relies on the SCS for 80 percent of its oil imports, claims nearly 90 percent of the SCS as its territory. This territorial “nine-dash line” declaration encompasses numerous surrounding islands and overlaps with the territories of every other nation bordering the SCS. Vietnam maintains claims to many of the island chains in the area, expanding its military and infrastructural presence in those areas despite overlapping with several other nations. Other Southeast Asian countries also declare competing entitlements, making this maritime space one of the most contested in the world.
As the political environment shifts, so too do the strategies of the actors operating in and around the SCS. China has expanded its presence in the region. The US has deepened its focus on maritime freedom. Japan and Australia have revised their defense postures. The Philippines has moved towards a more assertive approach. Together, these changes have transformed the SCS into a defining area for Indo-Pacific strategy.
This roundtable examines how five key actors—Japan, China, the Philippines, Australia, and the U.S.—currently approach the SCS and recommendations as to how they should continue. Their perspectives reveal both divergent national strategies and the pressures shaping regional security. Together, these analyses reveal the shifting realities of an Indo-Pacific region increasingly defined by competition and strategic uncertainty, shaped not by a single actor or strategy but by the unique security pressures, political constraints, and economic concerns facing each country.
China’s Naval Game
Miya Segal, GS ‘28
For China, modernization means survival. China’s naval expansion in the South China Sea represents a necessary effort to protect maritime territorial claims while simultaneously defending national security interests. China’s maritime security has become an existential concern, with roughly 80 percent of China’s energy imports passing through the South China Sea, a vital intersection linking the Pacific and Indian Oceans. In addition, over $3.4 trillion in annual trade passes through these waters. Thus, it is imperative for China to secure regional safety and freedom of navigation, especially in light of its expanding global economic role.
China’s strategic mindset regarding the South Pacific today is marred by a history of naval weakness. Throughout what is referred to as the ‘Century of Humiliation’ (1839–1949), China’s coasts were repeatedly penetrated by foreign forces, mostly Britain and France. Following the establishment of the People’s Republic of China (PRC) in 1949, sovereignty and territorial integrity, especially on the coast, became a non-negotiable for China’s sense of strength. The history of unease was compounded by the 1996 Taiwan Strait Crisis, in which U.S. aircraft carriers breached the region to signal support for Taiwan. In addition to further antagonizing China, the breach simultaneously promoted U.S.-Taiwan intelligence sharing and cooperation. Again, this situation crystallized China’s sense of helplessness in preventing foreign intervention on the water. Since then, maritime modernization has become central to China’s strategic independence.
China seeks to cultivate a navy capable of sustained operations in the Western Pacific. This shift is demonstrated by investments to develop new aircraft carriers, advanced submarines, and artificial island infrastructure in the South China Sea. Thus far, the decades of systemic investment have paid off: the Chinese Navy now operates 234 warships compared to the US Navy’s 219. Such capabilities intend to secure access and deterrence throughout the Pacific maritime sphere.
While China and its allies boast these successes, other regional and international stakeholders are intimidated by such developments. The U.S., for instance, maintains forward-deployed forces and alliance networks in the region to maintain maritime dominance. China perceives such acts as provocative and reciprocal behavior that it would not tolerate. Countries such as Japan, Australia, the Philippines, and Malaysia find themselves amid the global superpower scuffle between the U.S. and China. Of specific concern is the recent AUKUS partnership between Australia, the U.K., and the U.S. for the joint development of nuclear submarines and naval technologies. China perceives this initiative as oppositional to its hegemonic strength and fears expansions of such partnerships across the Indo-Pacific.
Still, some states find that cooperation with China is more beneficial than harmful. China signed trade and security agreements with the Solomon Islands and the Cook Islands in recent years, demonstrating that economic cooperation, mutual development, and infrastructure investments can be borne out of China’s expanding presence. Further, China scaled up aid efforts, totaling billions of dollars in foreign aid to the Pacific Islands, namely Fiji, the Cook Islands, and Papua New Guinea, over the past decade. Such endeavors are to the displeasure of states like New Zealand, which maintains authority over the Cook Islands, and was irked that the territory had acted autonomously to effectively side with China in this East-West divide.
Ultimately, China’s current policy is pragmatic, asserting influence without seeking to destabilize the region. For now, China’s signals highlight cooperative management over unilateralism. Agreements with the Pacific Island nations demonstrate this approach of combining security freedom with economic opportunities for smaller states. However, some states still perceive China’s expanding naval presence as a direct threat and signal future military escalations. Although the global naval status remains subject to change, for now, China’s naval trajectory in the Pacific only continues to rise.
A Delicate Balance: Protecting Japanese Interests in the South China Sea
Siyang Ding, CC ‘29
The waves of the South China Sea (SCS) may lie far from Japan’s shores, but they float the lifeblood of its economy and security. Indeed, three-quarters of its energy and a significant portion of its trade pass through these waters, making any escalation in the area threatening to Japanese interests. Japan’s approach to the SCS is a delicate one: it must ride a fine line, defending a rules-based order while avoiding any kind of escalation that could destabilize the region.
Japan has clearly framed China’s dispute over SCS territory as a clear violation of the United Nations Convention on the Law of the Sea. In its June 2024 press release, the Ministry of Foreign Affairs of Japan reiterated serious concern over actions that increase regional tensions and declared it opposes any unilateral attempts to change the status quo by force.
The SCS has long been a contested region: following World War II, it became a hotspot for territorial disputes. More recently, conflicting territorial claims by China (in particular, the “nine-dash line”), the Philippines, Vietnam, Malaysia, Brunei, and Taiwan have become increasingly confrontational, resulting in frequent encounters between civilian and military vessels.
From Japan’s perspective, this is not only an issue between regional nations and China; it’s a test of the international community’s ability to uphold peace and international law for smaller island states in the Asia-Pacific region. Japan, a “non-littoral state” without a coastline in the region, still considers the SCS as vital because it relies on its shipping lanes. This aligns with Japan’s broader concern: if freedom of navigation fails there, similar coercion could threaten its own waters in the East China Sea and the Taiwan Strait.
Japan’s policy, outlined by the Diplomatic Bluebook 2025, calls for an “effective, substantive, and legally consistent” Code of Conduct between the Association of Southeast Asian Nations and China. In the status quo, Japan’s SCS policy rests on three mutually reinforcing pillars: law, alliance, and expanding capacity.
First, Japan utilizes legal diplomacy, consistently supporting ASEAN efforts to finalize a Code of Conduct, and backs the 2016 ruling that invalidated China’s nine-dash-line claim. Anchored in international law and conduct, this lets Japan defend principle and interest without appearing partisan, particularly against its regional superpower.
Second, Japan bolsters its deterrence through critical alliances. The U.S.-Japan alliance dominates Japan’s military influence. In recent years, however, Japan has also expanded cooperation within the Quad (a diplomatic agreement between the U.S., Japan, India, and Australia). Frequent maritime exercises, joint surveillance missions, and information sharing build a stance of security assurance, particularly to smaller states in the region under China’s shadow.
Third, Japan’s strategy is heavily invested in capacity-building for its neighbors. Through its Official Security Assistance program, Japan provides patrol vessels, drones, and other military technology to Southeast Asian coast guards. Recently, Japan supplied ten 44-meter patrol boats to the Philippine Coast Guard and six refurbished patrol vessels to Vietnam, and later financed six more. These transfers deviate from the previous two pillars, shifting Japan’s stance from a donor to an enabler.
Despite these three pillars forming an integrated approach, where law grants legitimacy, alliances provide credibility, and capacity multiplies Japan’s reach, there are constraints that persist. As a non-claimant to the region, Japan has limited leverage in flashpoints and tight tensions with China in the East China Sea risks further escalation. Domestic policies further limit how aggressively Japan can act abroad under its pacifist constitution, although even these principles are subject to change under the new right-wing government. But in contrast to China’s aggressive assertion of rights and Australia’s reliance on AUKUS hard power, Japan situates itself in a measured middle ground, supporting alliances while maintaining credibility. Still, Japan must consider its ability to balance assertiveness with restraint to determine whether it remains a stabilizing force or risks being sidelined in a shifting regional order.
Islands of Possibilities: The Philippine Gamble
By Soenke Pietsch , CC ‘26
In 1999, the Philippines intentionally sank one of its vessels at the Second Thomas Shoal, an island off the coast of the Spratly Islands. Less than 200 miles off the Philippines' coast, the Second Thomas Shoal is well within its Exclusive Economic Zone (EEZ), and should therefore, under Article 57 of the United Nations Convention on the Law of the Sea (UNCLOS), be the sovereign territory of the Philippines. And yet, an increasingly aggressive neighbor to the North, the People’s Republic of China, has challenged this convention, both by brute force and by rejecting rulings by the International Tribunal in The Hague.
At heart, the Philippines faces a significant challenge in asserting its sovereignty over disputed waters in the South China Sea, locally called the West Philippine Sea. The core problem is overlapping maritime claims under China’s expansive “Nine-Dash Line,” which encroaches almost entirely on areas claimed by Manila and 90 percent of the South China Sea. The dispute entails sovereignty, access to fishing grounds, and control over untapped energy resources.
Under the previous president, Rodrigo Duterte, the Philippines took a conciliatory stance towards China’s aggression in the South China Sea, stemming from Duterte’s pro-China vision for the nation. Duterte’s successor, President Ferdinand Marcos Jr., has pursued a more radical agenda, “abandoning the established consensus, breaking conventional arrangements, and acting[...] impulsive, bold” as one recent report by the World Navy Research Center at the National Institute for South China Sea Studies puts it. Under the new leadership, the Philippines Coast Guard has tripled patrol areas and bolstered naval presence in contested zones, while simultaneously pursuing multilateral diplomatic channels within the Association of Southeast Asian Nations (ASEAN) and leveraging U.S. military alliances to deter further incursions.
In so doing, President Marcos Jr. has exploited the intensifying rivalry between the United States and China, placing not just the South China Sea at stake, but also risking potential involvement during a possible Taiwan conflict. The Philippines recognized that the South China Sea dispute was no longer solely a bilateral problem but increasingly linked with wider Indo-Pacific security dynamics. This realization has been accompanied by intensified efforts to deepen military cooperation with the United States, leveraging alliances such as the Enhanced Defense Cooperation Agreement (EDCA) to enhance deterrence against Chinese incursions.
The Philippines' current approach, which involves augmenting its military presence while engaging diplomatically through ASEAN and international legal mechanisms, continues to be a path favored by its neighbors. It joins countries, such as Japan, in calling for an “effective, substantive, and legally consistent” Code of Conduct between ASEAN and China. Yet, the increasingly aggressive tilt from President Marcos Jr.bears the risk of spiralling a regional conflict into an international one, though it also buffers the Philippines from an increasingly hostile China.
As a point of contrast, countries like Indonesia have sought a more neutral stance, balancing relations with China and the West, while Vietnam has pursued robust military modernization to assert its claims. Thus, the Philippines’ strategy reflects both a pragmatic recognition of its limited unilateral capacity and the strategic imperatives of partnering with the U.S. amid shifting great-power contests.
Perhaps more than any of its neighbors, the Philippines confronts the most challenging sovereignty disputes of this century, both due to its proximity to China and the naval power it faces at high seas (and close shores). It must be cautious in pursuing an assertive defense posture under President Marcos Jr., though, combined with sustained diplomatic efforts, the strategy represents a calibrated strategy to safeguard national interests amid rising regional naval powers and geopolitical rivalry. Like the rusting hull deliberately left on the Second Thomas Shoal, the Philippines’ presence in these waters stands as both a symbol of defiance and a declaration of enduring sovereignty against the tides of great-power ambition.
Australia and AUKUS: A Commitment to Failure?
Jay Jacobson, GS ‘28
For the first time in 80 years, the Australian Defence Force (ADF) updated its “Indo-Pacific” security posture, stating in the 2023 Defense Strategic Review (DSR) that China is Australia’s primary strategic adversary. In doing so, Prime Minister Anthony Albanese intended to align more closely with the security priorities of the United States. As a result, the DSR presented an interesting contradiction: it declared U.S. hegemony as meaningless while committing Australia to deeper integration with U.S. security policy. The current DSR wants Australia to be aligned with the U.S., ready for a regional conflict. But what does that concretely mean for Australian security?
This realignment breaks with prior policy, which viewed defense against direct threats from "small or middle power[s] in [the] immediate region” to be Australia’s primary concern. This was especially relevant in the 1999 East Timorese Crisis, when violent pro-Indonesian groups caused an international crisis. In response, Australia spent USD 653 million and deployed troops, stabilizing the area. The investment paid off and proved Australia’s prior strategies as effective and efficient.
Then, Prime Minister Scott Morrison departed from this proven strategy and pivoted to a trilateral partnership with the U.S. and United Kingdom dubbed “AUKUS,” cancelling a deal with the French company Naval Group in the process (a deal which was already controversial for being a break with an even prior deal with a Japanese firm). This departure shocked the French government and the Australian public. It forced Australia to compensate Naval Group $647 million for breaking the contract in 2022, and the twelve conventionally powered “Shortfin Barracuda” submarines, already produced, were sold to India.
This debacle worsened when more details were revealed: Australia would immediately pay the US over $240B in exchange for nuclear-powered Virginia-class submarines. Unlike previous deals with Japan or France, there is no timeline for the U.S. to supply them. Per AUKUS, nothing will be provided at all if the U.S. Navy determines it can’t spare the ships. Certain U.S. officials also suggested that nothing would be provided unless they were “deployed in U.S. interests.”
AUKUS has become an albatross around Albanese’s neck. According to the Trump administration, U.S. shipbuilding capacity is woefully underperforming. Currently, there is no indication that the U.S. will surpass its own shipbuilding estimates or provide the submarines Australia has already paid for. Even more uncertainty arose as President Donald Trump’s administration expressed skepticism towards AUKUS, even after Trump invited Albanese to the White House. The deal may not even survive long enough to fail.
Australians have already paid $241B without any guarantee of a return. In the process, consecutive Australian governments have alienated France, Japan, and China. In an interview with Reuters, a Chinese official noted that AUKUS forced China to reorient its strategy towards Australia. This is raising the temperature in the waters around China, especially as U.S. officials appear intent on preparing for an “inevitable” conflict in 2027. In a search to upgrade its naval power, Australia has sacrificed much in the realms of diplomacy, its citizens' money, and paradoxically, its military readiness.
So, what is Australian defense policy? Albanese’s government seems unsure, committing to antagonizing security positions with what has been Australia’s largest trade partner for years, while declaring the end of Pax Americana. These policies are not born out of necessity, with past defence strategies yielding better results. Australia’s previous focus on maintaining peace in Papua New Guinea and its peace-keeping operations in East Timor have proven to be effective.
The underpinnings of the DSR, AUKUS, and Sino-Australian relations acknowledge the confusing shift in mood. But while these shifts may have made sense when they were announced, the Trump administration adds another level of uncertainty to an already difficult situation. If the Sino-Australian relationship cannot be repaired and AUKUS made more equitable, then Australia risks committing to failure.
Restoring US Naval Dominance in the Pacific
Alexander Vincenti, CC ‘26
This year, on October 13, the United States Navy celebrated its 250th anniversary, and its importance in establishing American hegemony cannot be overstated. Recently, however, U.S. naval superiority has been challenged in the Pacific by upgrades in Chinese naval capabilities and the stagnating quality of American ship production.
The Navy is a longstanding and effective mechanism of enforcement at the U.S.’s disposal. The Navy possesses a tremendous amount of military power, featuring a well-balanced arsenal of nuclear-powered stealth submarines, fast destroyers, and aircraft carriers capable of launching air strikes across the globe.
The Navy's function goes well beyond combat, and threats to exercise its power are a threat in itself. Displays of naval force in the Pacific are routinely deployed to help the U.S. enforce its national interests. In 2018, a U.S. carrier docked in Vietnam as a show of strength of the U.S.-Vietnam alliance in the face of Chinese aggression. Similarly, in 2024, a destroyer sailed through the Taiwan Straight after Taiwanese elections to show its support for the island’s sovereignty. The Navy has also launched multiple freedom of navigation operations, pushing back against aggressive maritime claims from China and other countries. In 2016, a U.S. destroyer sailed through waters around Fiery Cross Reef, challenging excessive territorial claims made by China, the Philippines, and Vietnam.
The Navy is likewise critical to maintaining soft power in the Pacific. In 2004, an earthquake in Indonesia killed hundreds of thousands, and the U.S. Navy responded within days with humanitarian aid and relief. In the following weeks, American naval vessels transported 24 million tons of supplies, with Indonesian public opinion of the U.S. rising from 15% to 38% and international opinion doubling from 25 percent to 53 percent.
For three decades, China has been modernizing its maritime forces and threatening the U.S.’s firm lock on the Pacific. The Chinese navy now has more ships than the U.S. and is capable of advanced operations throughout the region. Investing heavily in anti-ship cruise and ballistic missiles, along with ship production, has allowed China to solidify its regional control and redouble its deterrence capabilities against U.S. naval operations. This development comes as China challenges U.S. hegemony and splits with the U.S. over key geopolitical disputes such as Taiwanese sovereignty and the Philippines’ territorial claims.
The U.S. has struggled to respond, with its ship production being expensive, of poor quality, and delayed. Unlike China, the American industrial base for shipbuilding is weak, with shortages in labor and building capacity. This not only threatens the current U.S. Navy construction but also reduces the potential for wartime shipbuilding. Furthermore, the U.S.’s desire to simply produce ship numbers to catch up has interfered with building advanced ships that can carry out more specific missions.
Production delays, in particular, have impeded the Navy as it fights to maintain its dominance in the Pacific. In 2019, two Virginia-class submarines were ordered per year until 2028, and as of last year, production was only at 60 percent of their target. Additionally, 12 Columbia submarines were ordered for 2030, and the first submarine has already been delayed by one year, with more delays expected. In both cases, a lack of shipbuilders, supply chain issues, and production capacity challenges were cited as the culprit.
A dominant U.S. Navy is crucial to protecting U.S. interests, and it is a vital tool in the Pacific to counter Chinese and Russian aggression. If the Navy is to preserve this dominance, Uncle Sam must invest in it. By creating and subsidizing new shipbuilding infrastructure and jobs, implementing naval and congressional oversight over the ship production process, and supporting its allied navies in the region, the U.S. can begin to meet the demands of the Pacific.
Conclusion
The perspectives in this roundtable highlight how the SCS sits at the intersection of state ambition and regional order. Each country approaches the SCS from varying motives and positions. At the same time, they all face the common reality that the region’s security environment is tightening, and decisions today will shape the area for decades to come.
States must balance a variety of factors when considering steps forward, and these national strategies reflect distinct priorities. For China, a path to controlling the SCS could be as simple as gaining the favor of other claimants, whether through trade pressure or military might to overcome Western influence in the region. For Japan, this would be a disaster; therefore, the country wishes to challenge China in any way it can, from enforcing international agreements to bolstering its military alliances. For the Philippines, to apply command over its sovereign territory, leaders have been mostly conciliatory towards China, but this has already begun to threaten its economic interests. As for Australia and the U.S., tensions between them over broken promises and flimsy deals continue to mount, and the U.S. is struggling to compete with China in the region.
The fate of the region remains thoroughly contested. The SCS could become a zone of contained competition, multilateral compromise, or confrontation, depending on the decisions being made now by the regional and global actors that connect the decisions. This roundtable makes one point clear: while the SCS’s future remains uncertain, the answer to the question of who controls it will profoundly shape the future of the Indo-Pacific and the wider world.
This Policy 360 roundtable was edited by Maytal Chelst, Eli Levy, Nathan Shurts, and Claire Thornhill.