Weird how Russia and China don't have a lot of exposure to that particular risk - ever since "Nordstrom 2"...
China is extremely exposed. It too is dependent on internet comms, and blowing up cables anywhere will have consequences.
It is also highly dependent on international trade and finance. If it goes about blowing up international cables this is going to start a retaliatory trade war and financial sanctions.
As for retaliation, Russia is also highly vulnerable to trade sanctions. It can sell very little petroleum through pipelines to friendly countries. It needs tankers, and these can easily be blockaded on the high seas.
What is Nordstrom 2? A dangerous shopping experience?