Singapore has been independent since 1959, while the USA got its own in 1776, and Britain has been around for more than a thousand years.
I don't think we can, yet, call Singapore a lastingly successful system, considering most of the time since its independence has been under a father or his son.
I don't think we can, yet, call Singapore a lastingly successful system, considering most of the time since its independence has been under a father or his son.