When the United States first stationed P-8A Poseidon maritime patrol aircraft in Singapore in December 2015, China objected sharply. Its Foreign Ministry described the move as a push toward “regional militarization,” warning that the aircraft’s advanced anti-submarine warfare (ASW) capabilities threatened China’s growing submarine fleet and reinforced what it saw as a U.S. effort to contain China. The deployment came amid heightened tensions, including a May 2015 incident in which Chinese naval vessels issued repeated warnings to a U.S. P-8A flying over disputed waters in the South China Sea.
Nearly a decade later, Singapore announced the acquisition of four P-8As for the Republic of Singapore Air Force. What China once denounced as U.S. militarization has now become part of Singapore’s own force structure.
So far, much commentary has focused on the tactical dimension of the acquisition: the fact that the Poseidon “plugs an anti-submarine gap and reaffirms Singapore’s close defense ties with the United States.” While accurate, this framing is incomplete. The acquisition reflects confidence in advancing its own national interests together with those of neighbors, major powers, and the wider maritime commons.
Singapore is Not an Island
“Singapore is Not an Island” is the title of former diplomat Bilahari Kausikan’s 2017 book, and its message remains salient to Singapore’s foreign policy analysis, which always includes a sober reading of the interests of others. China, the United States, and the country’s immediate neighbors continue to shape the strategic environment in which Singapore operates.
China’s interests in the region are obvious and extensive. In 2023, China imported about 11.28 million barrels per day of crude oil, much of which transited Southeast Asian chokepoints – most critically the Strait of Malacca, through which over 80 percent of its seaborne oil imports flow. Food supplies are equally exposed: China imported 99.4 million tonnes of soybeans in 2023, with Brazil providing roughly 70 percent and the United States about 20 to 25 percent. This dependence on maritime arteries shapes Chinese naval doctrine, which places submarines at the core of any potential Taiwan contingency, both to enforce a blockade and to deter outside intervention. Regional P-8 patrols directly complicate these plans by tightening surveillance of undersea activity across the very chokepoints on which China’s energy and food security rely.
For the United States, the priority is to prevent any single power from achieving regional hegemony. This logic dates back to the Cold War, when John Foster Dulles advanced the Island Chain strategy to contain Soviet and later, Chinese, power. The framework still shapes the U.S. force posture, which includes 50,000 troops in Japan, 28,500 in South Korea, access to nine Philippine bases, and rotational deployments in Australia. AUKUS will add nuclear-powered submarines, reinforcing the First and Second Island Chains.
Within this architecture, the P-8 Poseidon will act as a force-multiplier, extending surveillance and ASW. From Washington’s perspective, Singapore’s acquisition represents a form of increased burden-sharing that will help cover chokepoints like Malacca and the South China Sea, while reinforcing interoperability amongst U.S. partners in the region.
Singapore’s immediate neighbors – Malaysia, Indonesia, and Brunei – share many of the same vulnerabilities, shaped by the region’s long maritime history. Malaysia’s Port Klang handled about 14.64 million container units (TEUs) in 2023; Indonesia’s sea lanes carry a very large share of global shipping, especially through the Strait of Malacca; tiny Brunei’s economy is likewise heavily dependent on sea routes. These nations’ shared objective is maritime stability.
In this context, Singapore’s Poseidon purchase enhances security of the regional commons: It will soon be able to conduct long-range patrols, track submarines, deter piracy, and safeguard undersea cables. This will reinforce the stability that all four states depend on, while anchoring Singapore more firmly within the U.S.-led architecture that neighbors tacitly support as long as sea lanes remain safe.
Taken together, Singapore’s realist appreciation of these interests provides the foundation on which Singapore advances its own core interests.
Singapore’s Economic-Defense Compact
Then we come to Singapore’s own interests: namely, the fact that its status as a global economic node in Asia rests on connectivity. The Port of Singapore handled 41.1 million TEUs in 2024, second only to Shanghai’s 49 million. Vessel arrival tonnage reached 3.11 billion gross tons, more than Hong Kong and Busan combined. Unlike Shanghai, Singapore has no vast domestic market. Most of its throughput is transshipment, which makes uninterrupted sea-lane access essential.
Digital infrastructure is equally critical. In 2023, Singapore had 26 submarine cable landings across three landing sites and is projected by 2028 to be connected to more than 40 subsea cables, making it one of the most connected digital hubs globally. These cables are not just conduits of data but the backbone of finance, trade, and government services. They carry the vast majority of Singapore’s international traffic and support financial services that contribute a significant share of GDP. While estimates of potential losses from a major outage vary, even brief disruptions would reverberate across banking, logistics, and digital commerce. This dependence on resilient undersea connectivity makes cable security not a technical issue alone but a matter of economic stability and national security.
Finally, Singapore’s role as a leading aviation hub underscores the centrality of connectivity. Changi Airport handled over 67 million passengers and 2 million tonnes of cargo in 2024, placing it among the world’s top 10 busiest airports despite the city-state’s small size. By comparison, Bangkok handled 54 million passengers and Kuala Lumpur 48 million. Changi’s advantage lies in reach: more than 120 airlines operate more than 7,000 weekly flights to over 150 cities.
These figures underline why Singapore’s infrastructure is both world-class and acutely vulnerable. Defense capability is therefore not separate from economics but a precondition for its continuity – and the Poseidon acquisition makes that compact explicit by helping secure the economic arteries on which national survival depends.