Exactly. My intention with the post was not to advocate the sudden disconnection of the United States, but merely to illustrate the possible ramifications of the United States doing this to somebody else.
Actually blacklisting the entire U.S. would cause major disruptions. DNS would be thrown in to chaos, and many businesses would have to find new hosting. Such a move would put the internet, in general, into disarray for quite some time, until it can be adapted to function without the U.S.
I'm not in favor of blacklisting any country, not the U.S., not even Nigeria, in fact, I'm not in favor of any blacklisting at all, except where known spammers are concerned.
Sadly, I suspect that even if we do blacklist the entire U.S. for spam, your government would not react in the desired way. As we all know, the present American administration, and most of those that have come before it, find it very easy to point out a fault in others, but not to point out a fault in themselves.
For instance, if all European countries were to blacklist the U.S., your government would call it a first strike in an intercontinental trade war, instead of a desperate measure to block spam. They would probably leave it at that, because it is becoming hard to bully the E.U.
If, for instance, a small, push-over country like South Africa did it, the U.S. would most likely park half the Atlantic carrier fleet off our West Coast and demand we stop our actions, which are a threat to American interests. Simply because a lot of South African money is leaving the country through transactions with American web sites, which would stop happening if we took such an action.
If a country with no money did it, they would probably ignore it, as American businesses are a little bit like the Forangi from Star Trek. If there's no profit in it, they deny its existence.