In 1965, sinkie had the money, israel willingly provided the service. Its as easy as that.
The plan, which Singapore accepted, assessed that the "only viable solution" was to build up a citizen army of conscripts that was trained and led by a small regular force
This era already over and should be abolished. There is no threat to sinkie. Sinkie regular army is still larger than jiu hu's. In fact entire asean had small armies and spent very little on defence. And China imposing itself In south china sea caught them all by surprise. Philippines and Vietnam will suffer this problem most as Brunei and Malaysia already extracting oil and gas right to the middle of the south China sea. If area in dispute with vietnam,, they merely do a joint drilling and sort matters out.