How to block outgoing traffic to a specific country?

Question

Computer networks

I want to close access on my home PC to all outgoing and incoming traffic to Japan, China, Singapore.
What program can do this?

Answer 1

Any firewall, but without a reinforced concrete guarantee that everything is blocked. Lists of subnets by country are freely available.

Answer 2

I did this https://blog.radjah.ru/2016/04/iptables-geoip.html
But xs how it will be under load.