As Singapore celebrates 50 years of independence, ongoing regional and domestic crises around the world provide a stark reminder to the city-state of the vulnerability of national security. Singapore’s innate sense of vulnerability has derived from its physical size, geostrategic location, history and its lack of natural resources. As a small state, it has traditionally focused on deterrence and diplomacy as the twin pillars of its national security policy. Central to Singapore’s national strategy has been the preservation of its sovereignty and independence. Among the vast array of deterrence and diplomatic instruments that Singapore possesses to deal with its own vulnerability lies a “relic of the past”: the Five Power Defence Arrangements (FPDA). The latter has enabled Singapore to both strengthen its own military capabilities as well as to follow a policy of external balancing through association with external powers. Established in 1971, the FPDA involves Malaysia, Singapore, Australia, New Zealand (NZ) and the United Kingdom (UK). It operates as a loose structure focusing on both traditional and non-traditional security issues, such as maritime security, terrorism, and humanitarian assistance and disaster relief (HADR), which are of direct concern to its participants.  e FPDA is arguably the oldest institutional expression of defence diplomacy in Southeast Asia today, and predates other military-to-military institutions such as the Association of Southeast Asian Nations’ (ASEAN) ASEAN Defence Ministers’ Meeting (ADMM) by at least 35 years. The FPDA was created amidst fears and uncertainties stemming from the 1967 announcement by the British Labour government of its new policy of military withdrawal from East of Suez. The British decision to disengage militarily was of particular concern to both Singapore and Malaysia as both states relied heavily on their military ties with London. The 1967 decision was tempered somewhat as the subsequent British Conservative government sought to maintain some military engagement in the Southeast Asian region and thereby proposed to replace the 1957 Anglo–Malayan Defence Agreement (AMDA) with the FPDA. With this origin in mind, it is clear that the FPDA was an instrument created to deal with the concerns of the time and especially with the insecurity felt by its Southeast Asian participants at an early stage of their independence.