The Five Power Defence Arrangements (FPDA), are a series of defence relationships and mutual cooperation established by a series of multi-lateral agreements between Australia, Malaysia, New Zealand, Singapore, and the United Kingdom (all Commonwealth members, with the first four once belonging to the British Empire) signed in 1971, whereby the five powers are to consult each other "immediately" in the event or threat of an armed attack on any of these five countries for the purpose of deciding what measures should be taken jointly or separately in response.