By: Salman Rafi SheikhIndonesia considers the J-10For decades, Washington has styled itself as Southeast Asia’s primary supplier of weapon systems. The US military footprint and arms sales across the region have long been pillars of American influence, projecting power in a strategically vital and economically dynamic part of the world. But beneath this enduring narrative, a profound—and mostly underappreciated—shift is underway.Beijing, known primarily as an economic powerhouse, is quietly but steadily expanding its role as a defense partner, embedding itself deeper into the military fabric of the region and ensuring its strategic primacy in any potential conflict.Chinese-made fighter jets, drones, naval vessels, missile systems, and surveillance technologies are increasingly common sights in the arsenals of Southeast Asian states. This is not a mere swap of suppliers. It signals a seismic recalibration with far-reaching implications.As more nations in the region grow reliant on China for their critical defense needs, their operational independence, particularly in potential conflicts with Beijing, faces subtle but serious erosion. For China, however, it is a real win-win situation. Not only is it exporting more, but also ensuring that its buyers would not be able to use Chinese weapons against China.The New Arms Landscape: China’s Growing GripThe August 2025 report from the Lowy Institute on Southeast Asia’s evolving defense partnerships laid bare the extent of Beijing’s inroads. According to the analysis, China has already entrenched itself as the primary defense partner of Laos and Cambodia, two of the region’s closest allies. More strikingly, China has supplanted the US as Thailand’s main defense supplier in recent years, leveraging the fallout of Washington’s chilled relations with Bangkok after the 2014 military coup.But the pivot is not confined to the “mainland” Southeast Asian states. Maritime nations, long considered more aligned with the West, are now reassessing their options. Indonesia, a key regional heavyweight, is reportedly considering Chinese J-10c fighter jets, weighing them against Western competitors like Israel’s Rafael jets. This prospective deal gained momentum following Pakistan’s successful deployment of the J-10 in recent clashes against India in the “5 Day War” in May, which caught the attention of Indonesian defense planners.Deputy Defense Minister and retired Air Marshal Donny Ermawan Taufanto underscored the seriousness of China’s overtures: “We have had talks with China, and they offered us a lot, not just J-10, but also ships, arms, frigates,” he told Reuters. While Indonesia is still evaluating system compatibility, after-sales support, and pricing, this openness to Chinese platforms signals a willingness to diversify away from traditional suppliers. The broader context is clear: Jakarta is hedging its bets amid rising regional uncertainties and a more assertive China.The strategic weight behind this trend was further emphasized in April when China and Indonesia held a high-level “2+2” dialogue in Beijing, bringing together foreign and defense ministers to discuss security, defense, and regional issues. This signals a diplomatic and military deepening of ties that goes well beyond transactional arms sales.Exercises, Dialogues, Deeper EngagementChina’s influence extends beyond hardware sales. It is actively fostering military-to-military ties through joint exercises and defense dialogues across the region, embedding itself as a partner in training, operational readiness, and strategic consultation.Thailand, for example, has been hosting annual “Falcon Strike” joint air force exercises with China since 2015, with the latest iteration in 2024 at the Udorn Royal Thai Air Force Base. These drills focus on enhancing combat readiness and practical interoperability, signaling a maturing relationship between the two air forces.Cambodia’s military cooperation with China is similarly robust. The “Golden Dragon 2024” exercises focused on counterterrorism and humanitarian assistance, with Cambodian Defense Minister Tea Seiha affirming the country’s openness to engaging all nations militarily—a stance that highlights Phnom Penh’s balancing act amid great power rivalry.Since 2017, China and Laos have conducted regular “Peace Train” exercises emphasizing humanitarian assistance and disaster relief. The continuation of these drills through 2024 underscores a longstanding and growing military relationship designed to extend China’s influence beyond pure combat capabilities.China’s defense engagement isn’t limited to less-aligned states. Even Singapore, a stalwart US partner, has quietly deepened military ties with Beijing. In 2019, Singapore and China updated a defense agreement to enhance bilateral military exercises, mutual logistics support, and institutionalize regular dialogues between defense ministers.These activities formalize and expand interactions between Singapore’s Ministry of Defence and the People’s Liberation Army, including port visits, joint exercises, official exchanges, and cross-attendance of military courses. Such cooperation reflects Singapore’s pragmatic approach to security—engaging multiple powers to ensure regional stability and safeguard its national interests.Similarly, the multilateral “Aman Youyi” exercises, which began as a China-Malaysia table-top drill in 2014, have blossomed into a comprehensive land and sea exercise involving multiple Southeast Asian countries, including Cambodia, Laos, Malaysia, Thailand, and Vietnam. The 2023 iteration reaffirmed China’s commitment to deepening its multilateral defense presence.Meaning Southeast Asia and WashingtonThe implications of this shifting defense landscape are profound. First, as Southeast Asian nations acquire Chinese military systems and engage in joint exercises, their operational dependence on Beijing grows. This interdependence could seriously constrain their ability to act against Chinese interests in critical flashpoints, especially in the South China Sea, where territorial disputes and strategic competition remain highly volatile.Second, the Chinese model—offering competitive pricing, flexible terms, technology transfers, and political non-interference—appeals to countries wary of the strings often attached to Western arms sales. This makes Beijing an attractive partner for nations seeking to modernize their militaries without becoming beholden to Washington or its allies. This is further compounded by the inability of the West overall to even present itself as a reliable military partner.Third, doubts about the reliability and consistency of US engagement continue to mount. Washington’s uneven policies, including responses to military coups or political crises in Southeast Asia, have left some governments questioning America’s long-term commitment as a security partner. In contrast, China’s patient, steady approach appears to many as a reliable alternative. Plus, China’s ability to work with any and all types of regimes gives Beijing flexibility and regional state an unconventional partner.For the US, therefore, these developments should serve as a wake-up call. Maintaining the status quo is no longer sufficient. If Washington wants to remain relevant, it must reimagine its engagement strategy—not only through arms sales but by strengthening defense diplomacy, deepening joint exercises, ensuring technology transfer, and addressing the political sensitivities that matter to Southeast Asian leaders.Ultimately, what we see in Southeast Asia today is a calculated hedging strategy by countries caught between two superpowers. Southeast Asian leaders are navigating an increasingly complex geopolitical environment where the US and China both vie for influence through economic ties, military cooperation, and diplomatic engagement.For the region, the stakes are high. The choices made now will define the military balance, economic development, and political stability for decades to come. As this new chapter unfolds, all eyes will be on Southeast Asia to see whether it can maintain strategic autonomy, or whether it will become another arena where superpower rivalry plays out with lasting consequences.