The geopolitical dynamics of Southeast Asia in the modern era are strongly influenced by various factors, including global change, great power competition, and regional challenges. This region is the center of attention because of its strategic position connecting sea and land between Asia and Oceania. Among the main actors in Southeast Asian geopolitics are the US, China and the ASEAN countries themselves. China’s presence as a growing economic and military power adds to the complexity of geopolitical dynamics in the region. China’s Belt and Road initiative has led to major investments in Southeast Asian infrastructure. While this could encourage economic growth, many countries are concerned about the potential loss of sovereignty and over-dependence on Beijing. The existence of projects such as Gwadar Port in Pakistan and CPEC have become clear examples of China’s broader geopolitical ambitions. Meanwhile, the US continues to try to maintain its influence in this region through the Indo-Pacific strategy. Closer military and economic cooperation between ASEAN countries and the US, as well as participation in forums such as the ASEAN Regional Forum, are part of efforts to balance China’s influence. US commitment is visible through security programs, military exercises and trade agreements aimed at strengthening bilateral relations. In the ASEAN context, this organization plays a key role in easing tensions. With the principle of non-intervention, ASEAN seeks to create stability in this diverse region. However, challenges arise when member countries have diverse interests, especially in the South China Sea issue. Disputes over territorial claims between several member countries require careful diplomacy so as not to damage regional cohesion. Social dynamics, such as population movements and growing urbanization, are also changing the geopolitical landscape. The rising middle class in countries such as Indonesia and Vietnam is creating new markets and influencing foreign policy. Issues such as climate change also affect stability, as natural disasters can trigger migration and resource conflicts. Technology also plays an important role in Southeast Asian geopolitics. Cybersecurity, digital communications and information warfare are becoming new arenas of competition between major countries, which strengthens the need for collaboration in the field of technology between countries in the region. Technology-based collaborative projects can help strengthen economic and social resilience. Environmental issues, such as forest degradation and the water crisis, make cross-border cooperation increasingly important. Southeast Asian countries must work together to address this problem to have a positive impact on society and maintain long-term stability. This collaboration through forums such as the Mekong River Commission and the ASEAN Working Group on Climate Change is very crucial. Overall, Southeast Asia’s geopolitical dynamics are rich with complex challenges and opportunities. Major players, both large countries and regional organizations, are constantly looking for ways to adapt to change, creating a new balance in international interactions. Building mutually beneficial relationships and responding effectively to regional challenges is key to the region’s future stability and prosperity.