1) Rapid identification and localization of breaks, so military/police forces can be dispatched to the area.
2) Continuous deployment of MQ-9B SeaGuardian or HALE UAV platforms around shallow cable runs to locate and id dark ships, who would also be running nav beacons before and after.
3) Low-earth-orbit persistent sensing networks (e.g. what's now called PWSA [0]) with ship id'ing sensor packages.
As parent notes though, the lynchpin of this is inverting the cost:benefit ratio to be unfavorable, by raising the likelihood that ships will be detained and ultimately seized.
Even oligarchs don't like to light money on fire.
[0] https://spacenews.com/space-force-preparing-for-the-age-of-p...
Russia's war with Ukraine is not profitable for Russian oligarchs or Russia itself yet it continues
Europe's response has been and continues to be nothing less than shambolic and shameful.
[1] https://www.theguardian.com/world/2025/feb/24/eu-spends-more...
Yes, some Russian oil still makes its way to Europe, often through indirect routes. In 2023, the EU imported 130 million barrels of refined products from refineries processing Russian crude, adding about €1.1 billion in tax revenue to Russia (https://www.globalwitness.org/en/campaigns/fossil-gas/eu-pur...). The EU is working to close these loopholes.
Meanwhile, EU financial aid to Ukraine in 2024 stands at €18.7 billion, compared to €21.9 billion paid for Russian fossil fuels (https://energyandcleanair.org/publication/eu-imports-of-russ...). But military support tells a different story: the EU and member states have committed €48.7 billion in military aid, including tanks, air-defense systems, and fighter jets (https://www.consilium.europa.eu/en/policies/military-support...).
The claim that Europe is buying more from Russia than it’s giving Ukraine ignores the scale of military aid and the long-term shift away from Russian energy. It’s not perfect, but it’s far from "shambolic."
The current approach, to zig-zag over a cable with the anchor, is extremely obvious, but they could just as well have an entire fleet of ships just casually drag their anchor when passing over their targeted cable until one of them catches it. With a bit of planning, a large number of unrelated ships could be over one or more cables at the time the cable snaps, making it rather difficult (and therefore expensive) to figure out which ship is behind the attack.
The value of their crude oil fleet is also rather diminished by sanctions now that they can't sell as much crude oil as they could before.
For this specific attack, the ship being forfeited would be a net win. However, for the many other sabotaged cables, that's not happening. I think Russia gladly pays a couple thousand euros a day to sabotage European communications for weeks, as well as trick European/NATO fleets to show themselves and demonstrate how they behave when they're looking for trouble.