Introduction

Located between China, India and two oceans, Southeast Asia is of geostrategic significance in the Indo-Pacific arena, and despite being limited, the region's military power is indispensable to the security of each country, the region and beyond. Placed between the Pacific and Indian Oceans, the sea lines of communication (SLOCs) through the region are strategically and economically significant. Major East Asian economies such as China, Japan and South Korea rely heavily on these SLOCs for trade in energy, raw materials and other goods. Other major economies such as the United States are also increasingly depending on these SLOCs for global trade. Disrupting the SLOCs will not only directly affect those countries but also have spillover effects worldwide. For example, those SLOCs are strategically crucial for the great powers that move their navies between the two oceans. In addition, the SLOCs, which pass through the vulnerable chokepoint of the Malacca Straits, are a lifeline for China, because the majority oil supply passes through there. The reliance on SLOCs leads to what former Chinese President Hu Jintao once described as the “Malacca Dilemma,” which could affect the global balance of power if the passage is impeded. ¹ Furthermore, the unsettled territorial disputes in the South China Sea, involving many Southeast Asian countries and China, have become a major stage for geostrategic confrontation or competition between China and the Quad countries, namely the United States, Japan, India and Australia.