In connection with the New York Times article about the Russians not even contemplating cutting honest Western undersea cables - that article seems like another attempt of the US Navy and industry to boost the sales prospects of the US Unmanned Underwater Vehicles (UUVs).
Undersea cables were first laid in the 1850s between Britain and Europe and between Britain and US-Canada. Cables have been broken by human (fishing trawlers, poor leaky cable insulation material and anchors) and natural (earthquakes, currents, bitey sharks and whales) activity. A number of ports, such as Halifax, Canada, near important cable routes became homes to specialised cable repair ships.
This useful book link indicates submarines, very early on, were also active in cable cutting. "The U-151 [in 1918] also cut the undersea cables between New York and Nova Scotia and New York and Colon, Panama."
U-151 had an amazing performance then and now. It was built in 1916 (World War One) 1,500 tons (surfaced), 18 torpedos, 2 x 6 inch guns, 56 crew and a range of 25,000 nautical miles.
[As an aside - the century old U-151's specifications beg the question "Why does Australia in 2015 think an extra large 4,000 ton (surfaced) conventional submarine is necessary to give 11,000 nautical miles - less than half the range of U-151 a World War One submarine?]
At the beginning of World War Two Atlantic cables would have been cut in 1939, mainly by surface ships. In the Pacific the Japanese advance was so fast that allied cable cutting sometimes took until 1945. "/C" commented October 25, 2015 at 7:49 PM at http://gentleseas.blogspot.com.au/2015/10/south-korean-hhis-hds-400-small.html about British XE-class mini-submarines used to cut Japanese undersea cables in 1945 between Hong Kong and Saigon and between Hong Kong and Singapore.
One of the cutters was Max Shean from Western Australia doing very hazardous duty.
Since 1945 cables continue to be broken by fishing trawlers, anchors, earthquakes, currents, and bitey sharks. In response to this threat to the communications network, the practice of cable burial has developed. Still, cable breaks are by no means a thing of the past, with more than 50 repairs a year in the Atlantic alone, and significant breaks in 2006, 2008, and 2009.
In a major war cable cutting has three main advantages:
1. It immediately disrupts an enemy's international communications.
2. It also immediately disrupts domestic communications because, in the digital age, much of the internet AND telecommunications between major cities of the same country rely on international servers and links.
3. Having lost international cables an enemy is forced to use satellites, microwave links and other radio links. Since the beginning of World War One cables have been cut, in part, because subsequent reliance on radio links is much more easy to intercept - see https://en.wikipedia.org/wiki/Submarine_communications_cable#British_dominance_of_early_cable