The Straits of Malacca and Singapore are a single, continuous waterway and a critical geographical concept, forming the shortest sea route connecting the Indian Ocean (via the Andaman Sea) and the Pacific Ocean (via the South China Sea). This approximately 520 nautical mile channel is the longest strait used for international navigation.
Its origin as a major global artery dates back centuries, but its modern legal framework was solidified by the 1982 United Nations Convention on the Law of the Sea (UNCLOS). The problem UNCLOS solved was balancing the sovereignty of the bordering states—Indonesia, Malaysia, and Singapore—with the global need for free navigation, especially as coastal states extended their territorial seas to 12 nautical miles after World War II.
The mechanism governing the Straits is the transit passage regime, established under Part III of UNCLOS. This regime grants all ships and aircraft the unimpeded right of passage for continuous and expeditious transit, which is a stronger right than the "innocent passage" applicable in typical territorial seas. The Straits are a major global choke point, with approximately 60,000 to 70,000 vessels transiting annually, carrying about one-third of the world's traded goods and a significant portion of oil and LNG to East Asia.
A key related institution is the Cooperative Mechanism, launched in 2007 by the three littoral states, which brings in user states and the shipping industry to voluntarily share resources for navigational safety and environmental protection. This mechanism, along with the Tripartite Technical Experts Group (TTEG), represents a recent change, formalizing cooperation to manage the heavy traffic and environmental risks. The core principle of transit passage under UNCLOS remains the same, but the operational governance has been enhanced through this cooperative framework.