The FPDA was set up following the termination of the United Kingdom's defence guarantees of Malaysia under the Anglo-Malayan Defence Agreement, as a result of the UK's decision in 1967 to withdraw its armed forces east of Suez. Under the Five Powers Defence Arrangements, the five 'powers' (Australia, New Zealand, Malaysia, Singapore and the UK) are to consult each other "immediately" in the event or threat of an armed attack on any of the five countries for the purpose of deciding what measures should be taken jointly or separately in response. There is no specific commitment to intervene militarily." The FPDA provides defence co-operation between the countries, establishing an Integrated Air Defence System (IADS) for Peninsular Malaysia and Singapore based at RMAF Butterworth under the command of an Australian Air Vice-Marshal (2-star). RMAF Butterworth, was under the control of the Royal Australian Air Force until 1988, and is now run by the Royal Malaysian Air Force but hosts rotating detachments of aircraft and personnel from all five countries.