[Scythian]

quite a silly idea.
national defence can only depend on locals. locals home, asset most people in singpaore.
also no place to run. so in war more likely to defend your asset, life and love one.
foreigner for money only.
foreigner can only be a complement

As Reported 1% of Singaporean family owns 34% of Singapore's wealth.

How much do you have worth defending?

Note
You should make them pay for engaging professional Gurkhas to defend SIngapore