Two undersea cables in Baltic Sea disrupted

So what's the solution ? Assign a surveillance UAV to every Russian ship parked "without a good reason" over a cable ? It would be expensive, but doable, and create a reserve of vehicles for wartime use.

Why would they use a Russian flagged ship for that?

It's harder to get false identification then people on the internet think.

But also the Russian MO has never been to do things where it's not obvious they did it: the spate of critics of the Russian government dying by falling out of windows isn't because they lack creativity in assassinating people.

You don't need false documents, buying and operating a ship that has no direct ties to Russia and is registered at an other country isn't that hard at all. Of course yeah, if suddenly if cables get cut 10x more often that they used to it be pretty obvious who is behind it regardless.

> has never been to do things where it's not obvious they did

They could still shot them or something like that, the window thing still grants them some plausible deniability. e.g. the ship that (unclear if intentionally) damaged the cables last year was Chinese.

> You don't need false documents, buying and operating a ship that has no direct ties to Russia and is registered at an other country isn't that hard at all

You literally just described a program of falsifying documents! If you're buying and operating a ship, then to have "no ties to Russia" while using Russian money, someone is showing up with forged paperwork or some off-the-books bribes to make that happen.

Drawing down those sorts of sums from a country's treasury isn't something you can actually just "do" - people have to take actions, funds transferred, meetings held and operations authorized.

You are describing a system of resources which likely does exist, but is by no means easy to use or acquire and would not be expended unnecessarily.