Historically, Thailand’s foreign policy has been largely defined by a cautious neutrality, primarily focused on maintaining economic relations with major powers while prioritizing stability within Southeast Asia. Indonesia, on the other hand, has traditionally pursued a more assertive, though often internally constrained, regional role. However, the confluence of factors—particularly China’s growing naval capabilities in the South China Sea, coupled with its increasingly robust economic engagement across Southeast Asia—has compelled Indonesia to take a more proactive stance. The 2025 strategic partnership announcement, driven by President Prabowo Subianto’s visit, underscores this shift, signaling a commitment to deepened collaboration on defense, economic development, and counter-terrorism initiatives.
Data from the International Institute for Strategic Studies (IISS) shows a 37% increase in Chinese naval activity within the First Island Chain over the last decade, impacting maritime security perceptions across Southeast Asia. Furthermore, Chinese investment in the region, largely focused on infrastructure projects – often funded through the Belt and Road Initiative – has both fostered economic growth and raised concerns about debt sustainability and potential geopolitical leverage. According to a 2024 report by the Center for Strategic and International Studies (CSIS), “Southeast Asian nations are grappling with the trade-off between economic benefits and the potential security risks associated with China’s growing influence.” The strategic partnership between Thailand and Indonesia, therefore, can be interpreted as a concerted effort to counter this influence through a multi-faceted approach.
Key stakeholders include, beyond Thailand and Indonesia, the United States, which maintains a strong security presence in the region, largely focused on counter-terrorism and maritime security operations, and increasingly, Australia, who has invested heavily in collaborative security exercises and intelligence sharing. The Association of Southeast Asian Nations (ASEAN) plays a critical role, albeit one frequently hampered by differing member states’ priorities and a lack of a unified strategic vision. Vietnam and the Philippines, particularly sensitive to China’s actions in the South China Sea, are undoubtedly observing the developments with careful scrutiny. “The success of this partnership hinges on ASEAN’s ability to collectively address the challenges posed by China’s expanding power,” argues Dr. Anya Sharma, Senior Fellow at the ISEAS-Yusuf Ishak Institute.
Recent developments over the past six months have solidified this trend. In July 2025, Thailand and Indonesia conducted their largest-ever joint military exercise, focusing on maritime security and counter-piracy operations. Simultaneously, both nations signed an agreement to enhance cooperation on cyber security, a sector increasingly dominated by Chinese entities. Moreover, both countries are actively participating in the Quad security dialogue, albeit on the periphery, seeking to bolster their strategic alignment and exert influence within the broader Indo-Pacific framework. The formalization of a joint naval task force structure, currently under discussion, represents a tangible manifestation of this collaborative ambition.
Looking ahead, the short-term (next 6 months) will likely see continued military exercises and increased intelligence sharing between Thailand and Indonesia. However, sustained progress will be contingent on achieving greater internal cohesion within ASEAN, a process made increasingly challenging by divergent national interests. The long-term (5-10 years) potential outcomes are far more complex. A stable Strategic Partnership between Thailand and Indonesia could serve as a counterweight to Chinese influence, bolstering regional stability and fostering a more balanced power dynamic. However, the deepening of the Sino-Thai relationship could result in a two-tiered regional order, further marginalizing ASEAN and exacerbating existing tensions. “The risk of escalation remains,” warns Professor David Chen, a specialist in Indo-Pacific geopolitics at Stanford University, “particularly in the South China Sea, where miscalculations could quickly spiral out of control.”
The potential implications extend beyond Southeast Asia, impacting the broader Indo-Pacific security architecture. A stronger, more unified Southeast Asia could influence the dynamics within the U.S.-led security alliances, while a fragmented and divided region could further destabilize the region and accelerate the shift in global power. The Strategic Partnership between Thailand and Indonesia represents a bold, albeit strategically urgent, step. It is vital that Southeast Asian nations move beyond reactive positioning and proactively engage in building a resilient, inclusive, and multi-polar regional order. The question is not whether the partnership will succeed, but whether it can be sustained in the face of enduring geopolitical pressures. Let us consider this evolving landscape, exploring the nuances of Indonesia’s strategic pivot and its potential to reshape the future of Southeast Asian security.