Not as bad as you might think. One of the strengths of the Internet is that there are multiple pathways that data packets can take. Cut an Atlantic line joining North America and Europe, and the traffic will be rerouted to another cable from North America to South America to Africa to Europe.
that is why I said “cut all of these cables”
I understand that if only one cable was cut there would be rerouting, but if all were cut many countries would be without for a long time.
Note that your map shows the large bandwidth between Asia and US, as well as Europe and US, while bandwidth between Asia and Europe is limited.
During the time of day when Asia and Europe traffic peaks, there is relatively limited Asia - US and US - Europe traffic.
It is also nighttime in the US, so our east-west fiber links
across the US are idle.
To use the otherwise unused capacity, Asia and Europe traffic is transited via the US. This also gives NSA a fine opportunity to monitor it.
Note that most traffic between Asia and Latin America, as well as traffic between Europe and Latin America also transits nodes on the US east and west coasts.
You map still shows a relatively minor number of cables to cut and there are peer adversaries that could pull off the feat of cutting every one of them.