Tunku made a good decision. The Brits would not have the might, will or finance to stay and defend Malaya, the sun had set in their empire. The newly formed Federation would be vulnerable to a hostile Indonesia and Sarawak and Sabah would've been lost. Malaysia at that time was not in a position to fend for herself. Indonesia was just waiting for something like that to divert attention from home woes and would have loved the incident to escalade. It was in the better interest of South-East Asia that Suharto came to power later.
Cheers!
Read this particular book about the The Confrontasi as a student..
After WW2, the British were really in trouble with their finances.. It worsened after India, Burma and many African countries gained independence.. The British then depended on Malaya to enrich their already crumbling Empire..
In fact they were starting to roll in tonnes of money thanks to Malaya's tin and rubber.. The demand for rubber worldwide in the 50s and 60s made the British very rich and rubber supply from Malaya kept the British economy going..
Thats why the British could afford to send in troops from Rhodesia, Fiji to help fight alongside the rest of the Commonwealth troops that were already based in Malaya.. They even brought in their famed SAS unit for the Emergency..
In fact they were rich enough to buy helicopters and despatched those choppers deep into the Malayan jungles in the fight against the Commies..
In fact the Malayan Emergency was the first time helicopters played a major part in any war and it was one of the main reasons why the Commies were defeated..
If not for Malaya's riches, the British would not be defending her for so long against the Indonesians and The MCP..