Australian troops who joined New Zealanders to fight a secret war against Indonesia in the early 1960s have been staging a reunion in Sydney this weekend.
The British-led force helped the new Malaysian federation to fight Indonesian incursions, with New Zealand soldiers mounting covert cross-border raids into Indonesia.
The conflict resulted from a belief by Indonesia's then-president Sukarno that the Malaysian federation was a British attempt to maintain rule while appearing to be granting independence to the former colony, the ABC reports.
The term Konfrontasi - meaning confrontation - was coined in 1963 by Indonesia's foreign minister at the time, Subandrio, and came to refer to Indonesia's attempt to destabilise and break up the new federation.
A service was held in Sydney on Saturday to commemorate 50 years since Australian troops departed for the Indonesia Confrontation.
At the time, cross-border operations were top secret, and the conflict received very little coverage in the news media.
Australian soldiers were under strict instructions to tell no-one about the conflict, not even their wives. They kept the secret for 30 years.