When the British forces withdrew from East of Suez, Aussies and Kiwis took over some of the facilities and roles the Brits had played, but far few in numbers.
(They did keep Bugis Street alive and humming though)
The Five Power Defense Arrangement is still in existence and hold annual exercises in the region, but not with permanent presents of foreign forces in Singapore, or Malaysia.
USAF has a small supply base and Air Force contingent in Singapore and the US Navy’s 7th Fleet make regular visits at Changi Naval Base.
The first 10 years or more after independence was tough in Singapore, with attempts to keep the population growth in check by the “Stop at Two” campaign and limitation on foreigners working here.
That included in the Maritime industry, which had been identified as a future growth area, with local and foreign owned shipping companies being encouraged to use the Singapore Ship Register. The problem was that there were few qualified Singaporean officers and local Maritime Education had just got underway. The Naval Base had trained some very capable Mechanics and the Royal Navy, RFA and MM some good Engine Drivers that became Engineers.
Lot of dispensations were issued to fill positions on the ships, but foreigners were still needed to fill top positions, both afloat and ashore.
One problem was that Singaporean Deck officers quickly found jobs as Harbour Pilots and left the ships before they got to hold command, or even serve as Ch.Officer. Engineers became Superintendents, or worked on the shipyards.
In the early 1970s I was Master on a Singapore flag ship, where I was the only one with a license eqv. to my position.
By the early 1980s Singapore encouraged labour intensive industry to move to other countries in the region to free up work force and factory space for more capital intensive industry with higher Value Added
Singapore even offered monetary support to Garment Manufacturers to move to Bangladesh and Electronic Assembly plants to move to Thailand.