Comment by toast0

Dropping traffic by source country is not that hard, if you assume country of ip registration is country of origin, which mostly works although things like multination networks, ip leasing or other reuse, and proxy/vpn can result in misattribution.

However, if you mandated blocking Russia or China at a national level, you would cause some major issues.

a) it would become very hard to communicate with people in China. That would make commerce with China very difficult. Blocking communication with your number 3 trading partner [1] is going to be a massive disruption.

b) Doing the same for Russia would be less disruptive as there's much less trade between the US and Russia, and significantly fewer immigrants to the US from Russia than from China. However, there's still a lot of connection between the US and Russia and that would be disrupted.

Given the success of the internet and the layering of everything else over it, I suspect cutting off internet would likely cut off phone service as well. Even postal mail might be impacted, as there is likely coordination between national agencies via the internet.

[1] https://en.wikipedia.org/wiki/List_of_the_largest_trading_pa...