This campaign was an extension of the conflict in Borneo where British and Malaysian troops were operating against Indonesian insurgents.
In 1964, the Indonesian President decided to attack the Malaysian mainland. Parachute landings were made in Johore while other troops managed to land across the Malacca Straits from Indonesian Sumatra.
It was for operations in Malaysia and surrounding waters against these troops that this clasps was instituted, as opposed to the concurrent Borneo operations.
The qualifying period was 30 days' service in the Malaysian Peninsula-Singapore area between 17 August 1964 and 11 August 1966.