The Five Power Defence Arrangements (FPDA) is an oft-overlooked regional security institution. It is a curious security device in the sense that it embodies several paradoxes. The FPDA's most important roles are not those which are usually discussed openly. The most important non-regional player in the FPDA is not necessarily the one which plays the more prominent role in terms of its conventional military commitment. And while the FPDA is apparently anachronistic, in reality it continues to serve vital security roles, and this is likely to continue in the future.

To expand on the first of these paradoxes: it is sometimes said that the FPDA is a Cold War leftover that is irrelevant to the current and future security concerns of regional states. However, this argument misses the point that, although the FPDA was created during the Cold War in the context of the United Kingdom's (UK) military withdrawal from Southeast Asia in the late 1960s and early 1970s, its key roles were never related only to the Cold War. The five powers involved have always held diverse FPDA's core rationales has always been essentially taboo.

The first of these implicit roles has been for the FPDA to act as a hedge against the resurgence of an unstable and threatening Indonesia which might endanger the security of Malaysia and Singapore, and perhaps also the wider sub-regional balance of power to the detriment of Australia, New Zealand and perhaps even the UK. While this has not been a realistic or immediate prospect since the FPDA was established in 1971, the ouster of President Soeharto in 1998, and the ensuing instability in Indonesia over the next three to four years, may have reminded FPDA members — and particularly Malaysia and Singapore — of the origins of the Arrangements in the wake of Jakarta's Konfrontasi of 1963–66. And while Indonesia's trajectory in terms of domestic stability and its willingness to play a constructive role regionally and internationally has seemed encouraging under the leadership of President Susilo Bambang Yudhoyono, there remain disquieting domestic political trends that could lead to the world's fourth most populous country becoming a less congenial neighbour in the future.