By Tarinee Gupta

Abstract:

Global oceans are rapidly transforming from neutral commons into contested, militarized arenas driven by intensifying geopolitical rivalries. This shift is evident in persistent U.S. naval deployments through key chokepoints and China’s fortification of artificial islands in the South China Sea. Regional powers like Vietnam, Japan, and the Philippines are also modernising their navies, adding to the military buildup across key waterways from the Indo-Pacific to the Mediterranean.

This growing militarization undermines international maritime law, threatens freedom of navigation, and expands the ambiguous ‘grey zone’ of sub-threshold conflict. The proximity of rival warships, submarines, and aircraft in disputed areas raises the risk of miscalculation, unintended escalation, and potential conflict, endangering maritime peace and stability.

I. Introduction

Once regarded as expansive, cooperative avenues for trade, exploration, and cultural exchange, the world’s oceans are increasingly becoming arenas of strategic competition and military posturing. Intensifying great power rivalries, shifting global power balances, competition over maritime resources, and technological advancements in naval warfare and surveillance have transformed strategic maritime zones—particularly the Indo-Pacific—into focal points of tension.

The United States continues to deploy carrier strike groups across critical choke points to maintain dominance, while China has fortified artificial islands in the South China Sea. Simultaneously, regional actors like Japan, Vietnam, and the Philippines are investing heavily in naval modernization. This global trend towards militarization undermines long-standing maritime norms, challenges freedom of navigation, and raises the risk of unintended conflict, signaling a profound transformation in the maritime order.

This paper seeks to explore: How is the increasing militarization of the world’s oceans reshaping international maritime law, regional security dynamics, and the balance of power among major and emerging naval actors? To address this question, the study will analyze the strategic motivations behind naval expansions, examine the implications for international maritime law and norms, and assess the potential risks of unintended conflicts, culminating in policy recommendations to mitigate escalating tensions and promote cooperative maritime governance.

 II. Strategic Competition in the Indo-Pacific

The Indo-Pacific region, encompassing critical sea lanes that facilitate a vast percentage of global trade and energy flows, has undeniably emerged as the central arena for twenty-first-century maritime strategic competition. At the heart of this intensifying rivalry lies China’s increasingly assertive posture, particularly evident in the contested waters of the South China Sea. Beijing has undertaken extensive land reclamation projects, transforming submerged reefs and shoals into substantial artificial islands. Recent satellite imagery confirms the deployment of sophisticated military systems, including possible counter-air and counter-ship capabilities, advanced sensor arrays, and hardened infrastructure designed to support combat operations.. This build-up significantly enhances China’s capacity for power projection, surveillance, and potentially anti-access/area denial (A2/AD) capabilities, aiming to assert its expansive, albeit legally disputed, claims over nearly the entire sea. Recent analyses, including satellite imagery, have highlighted the deployment of sophisticated systems, potentially including counter-stealth radar capabilities on disputed features, further amplifying regional concerns about Beijing’s military reach and intentions.

In direct response to these actions and the perceived challenge to the existing maritime order, the United States has significantly bolstered its military and diplomatic presence throughout the Indo-Pacific. A key component of this response involves conducting regular Freedom of Navigation Operations (FONOPs). These operations, executed by naval vessels like the guided-missile destroyer USS Dewey, which, as reported by the U.S. Navy, conducted operations near the Spratly Islands, are explicitly designed to challenge maritime claims Washington deems excessive under the framework of the UN Convention on the Law of the Sea (UNCLOS). While often focused on Chinese-claimed features, FONOPs are a global tool used to assert navigational rights and freedoms against various nations’ claims inconsistent with international law. Beyond FONOPs, the U.S. strategy involves strengthening alliances and partnerships (such as the Quad with India, Japan, and Australia, and the AUKUS security pact with the UK and Australia), increasing the frequency and complexity of joint military exercises, and promoting a vision of a “Free and Open Indo-Pacific” to counter Beijing’s influence and uphold the principles of free navigation and overflight essential for regional stability and global commerce. This dynamic interplay between China’s assertions and the U.S. counter-responses continues to define the tense security environment across the Indo-Pacific waters.

III. The South China Sea: Sovereignty and Tensions

The South China Sea remains a focal point of geopolitical tensions, with multiple nations asserting overlapping territorial claims over its strategic waters and islands. Despite the 2016 ruling by the Permanent Court of Arbitration, which invalidated China’s expansive claims, Beijing continues to fortify its positions, prompting neighbouring countries to respond in kind.​

In August 2023, satellite imagery revealed that China was constructing an airstrip on Triton Island, part of the Paracel Islands chain, which is also claimed by Vietnam and Taiwan. The airstrip, measuring over 600 meters, appears suitable for turboprop aircraft and drones. This development mirrors China’s previous efforts in the Spratly Islands, where it built airstrips, docks, and military systems on artificial islands. Triton Island already hosts a small harbour, helipad, and radar arrays, underscoring China’s intent to enhance its military infrastructure in the region.

Vietnam has responded by intensifying its island-building activities in the Spratly Islands. According to a Newsweek report from March 2025, Vietnam added approximately 692 acres of new land across multiple features in 2024, nearly matching the combined total of the previous two years. This expansion includes the construction of an 8,000-foot runway on Barque Canada Reef, capable of accommodating most military aircraft, and the development of new harbors and support facilities on other reefs. These efforts reflect Vietnam’s strategic intent to reinforce its territorial claims and enhance its military infrastructure in response to regional tensions.​

The escalating militarization of the South China Sea by both China and Vietnam highlights the fragile nature of peace in the region. As nations continue to assert their claims through infrastructure development and military enhancements, the risk of miscalculations and confrontations increases, underscoring the need for diplomatic engagement and adherence to international law to maintain stability.

IV. Maritime Militarization Beyond the Indo-Pacific

While the Indo-Pacific region remains a focal point of maritime strategic competition, similar patterns of militarization are emerging in other critical waterways, notably the Eastern Mediterranean and the Arctic.

In the Eastern Mediterranean, countries such as Turkey and Greece have intensified their naval activities, driven by disputes over maritime boundaries, energy exploration rights, and regional influence. Turkey’s deployment of naval vessels to escort drilling ships in contested waters has escalated tensions with neighbouring countries and the European Union. Greece, in response, has bolstered its naval capabilities and engaged in joint exercises with allies, including France and the United States, to assert its maritime claims and ensure regional stability.

The Arctic is witnessing a strategic shift as melting ice opens new navigable routes and access to untapped natural resources. Russia has significantly increased its military footprint in the region, reopening and modernizing over 50 Soviet-era military bases, including 13 airbases, 10 radar stations, and 20 border outposts. The country has also deployed advanced weaponry, such as S-400 air defense systems and hypersonic missiles, and established specialized Arctic warfare units trained for operations in extreme conditions. These developments underscore Russia’s intent to assert its interests and secure its economic future in the Arctic.. The United States and NATO allies have expressed concerns over these developments, leading to a renewed focus on Arctic security and the potential for great power competition in the High North.

These developments show a broader global trend where maritime domains, once considered arenas for cooperation and shared use, are increasingly becoming theatres of strategic rivalry and military posturing.

In the South China Sea, China has transformed civilian-looking island facilities—such as those on the Spratly Islands—into dual-use outposts equipped with missile systems, radar arrays, and airstrips, blurring the line between civilian and military infrastructure. These developments enable constant surveillance and power projection under the guise of lawful maritime activity, allowing China to assert expansive territorial claims without triggering direct military confrontation. Similar grey-zone tactics are employed in the Eastern Mediterranean and the Arctic, where military posturing is disguised as research or routine operations.

V. Conclusion: Charting a Course for Maritime Stability

Navigating these turbulent waters demands more than high-level rhetoric. Reinvigorating multilateral mechanisms—such as dedicating a special summit to “Maritime Confidence-Building Measures”—could translate shared principles into binding protocols, reduce the risk of collision, and signal to all states that the oceans remain, above all, conduits for cooperation. The expansion of militarization into other regions, such as the Eastern Mediterranean and the Arctic, indicates that this is not a localised phenomenon but a global challenge. The increasing deployment of naval assets, establishment of military infrastructures, and assertive maritime claims threaten the principles of freedom of navigation and the integrity of international maritime law. 

To navigate these turbulent waters, it is imperative for the international community to reinforce diplomatic engagements, uphold the tenets of international law, and invest in confidence-building measures. Multilateral forums and agreements must be revitalized to address the dynamics of modern maritime disputes and to prevent the escalation of conflicts. Ultimately, preserving the oceans as spaces for peaceful cooperation and shared prosperity requires concerted international efforts to balance national interests with collective responsibilities, ensuring that the seas remain conduits for connection rather than arenas of confrontation.

About the author: Tarinee is a second‑year B.A. LL.B. student at Jindal Global University, exploring the intersections of law, politics, and global affairs. She writes for Nickled and Dimed, uncovering underreported narratives that shape international norms. 

Image Source: South China Sea Buildup Brings Beijing Closer to Realizing Control – The New York Times