According to the New York Times, military sources are concerned about a spike in Russian naval activity near the locations of undersea cables.
Keir Giles, associate fellow of the Russia and Eurasia Programme at think tank Chatham House has been quoted as saying that such a plan would be possible, but it would be more of an inconvenience than much else.
But it could be used to control other countries which were depended on their undersea cables.
It is only going to work in locations where the internet geography is going to create a vulnerability in communications and there are parts of the world where such action might be considered viable, he said.
Ukrainian telecoms providers reported disruptions to a key internet exchange point and cable connections during Russian military activity in the Crimean peninsula in 2014.
The incident is mentioned in a Chatham House report on Russian information war tactics which is being published later this year.
He said the Russians have been building a lot of submarines lately and some specialised vessels. It wouldn’t be surprising that they would want to do this.
What is more likely is that the Russians might be hoping to tap cables in undersea locations, and the US is reported to have done this in the 1970s.
GCHQ and the NSA can intercept data communications at listening sites such as Bude in Cornwall, where a major transatlantic cable comes ashore in the UK.