China & Southeast Asia: A New Maritime Order?

China is increasingly establishing itself as a key player in shaping a Southeast Asian maritime order, driven by investment in the region’s blue economy and strengthened security ties with nations questioning U.S. reliability. The success of this order hinges on China curbing assertive behavior in the South China Sea and the availability of viable alternatives from other international partners.

China’s Growing Maritime Influence

China’s focus on the blue economy and maritime security aligns with the priorities outlined in the ASEAN-China Comprehensive Strategic Partnership Plan of Action (2026-2030). China, alongside the Association of Southeast Asian Nations, is investing between US$2.0 trillion and US$3.7 trillion (approximately A$2.8 trillion and A$5.2 trillion) from 2020 to 2050 in the blue economy, according to the Global Times. Initiatives include establishing green shipping lanes in the Strait of Malacca and supporting eco-friendly coastal aquaculture.

Beyond investment, China is actively leading multilateral efforts to shape the maritime environment. The nation both signed and ratified the Biodiversity Beyond National Jurisdiction Treaty and is currently bidding to host the treaty’s secretariat. This contrasts with the United States, which has only signed the treaty and withdrew from 66 international treaties in January, including this one.

South China Sea Tensions and Shifting Alliances

A significant challenge to a China-led maritime order remains the ongoing conflict and tensions in the South China Sea, where China asserts expansive, and largely disputed, claims. However, growing geopolitical uncertainty regarding alliances with the U.S. is prompting increased cooperation with China from several countries in the region.

Indonesia has agreed to a joint development project with China in areas of the sea with overlapping claims, despite concerns about the project’s legality. Malaysia and Cambodia also conducted military drills with China last year. Vietnam and the Philippines have expressed concerns about the reliability of the U.S. as an ally should regional tensions with China escalate. A leaked document revealed that senior Vietnamese defense officials are even planning for a potential “second US invasion.” Consequently, Vietnam has strengthened ties with China, holding its first joint military drill last year.

China initially proposed a ‘Maritime Community with a Shared Future’ in 2019, but faced skepticism due to its coercive behavior in the South China Sea and the perceived reliability of the U.S. as an alternative partner.

The Role of the United States and Future Prospects

Increasing uncertainty surrounding the U.S. commitment to the region is now driving Southeast Asian nations closer to China. The success of a China-led maritime order depends on two key factors: the availability of alternative partners for maritime cooperation and China’s behavior in the South China Sea.

Many Southeast Asian countries are questioning their reliance on the U.S. under the current administration, citing a perceived decrease in trust and violations of international law. It remains unclear whether other middle powers, such as Australia or Europe, can offer comparable levels of cooperation and resources. If China continues aggressive tactics in the South China Sea, resistance from the region will likely persist. However, increased cooperation from China could pave the way for broader support for its proposed maritime order.