If 1st gen PR, usually no need .
If 2nd gen PR (AKA 1st gen PR's son), it is a must, unless u ship
him out of sg and vowed never to return (because if he returns
mostly go DB AKA jail regardless he is aware or unaware of the
situation).
This also applies to family who shifted here with their children
which means if his son is let say 16, he is automatically being
selected for NS regardless he wants or dun wants to do because his
dad is consider as the 1st gen PR, he automatically is the 2nd gen.
And the biggest twist of all: Even the father gave up his PR, his
son lan lan still hab to do NS (kind of a black and white
thing).
So what do these foreign talents do?
They apply for work permits and get their children student pass so
they totally avoid the PR-NS trap.