One important question that I'm unclear on is how long it takes to fix one of these cables. If it takes months then that is quite a wide window in which an attacker could incrementally take down cables.

They could even blow up all cables at once. Maybe the explosives have already been placed.

Generally it can be fixed in days. They raise it from the sea floor and splice in a new cable section.

True but ships and crews with the equipment to do the repairs are limited. It's possible to overwhelm the repair capacities. Also, it takes time to physically travel between cuts so while cuts in the Baltic might take a week or two to fix, a cut in the Atlantic and one in the Baltic may take a week or two just for travel.

If someone will try to overwhelm the repair capacities for integral communications, they'll be dealt with like pirates - simply sunk and be done with.

Crazy that you can splice optical cable..

They actually have very cool devices that will automatically align and fuse two fibers and estimate the loss of the bond.

https://www.youtube.com/watch?v=JP_C0XLLyR0

how much do one of those bad boys cost?

The cheapest ones are surprisingly cheap at less than $1,000 and the highest end ones are $10,000

Today, we're going to talk to John Owens and learn about the process of splicing fiber: https://www.youtube.com/watch?v=1zN20ZVInfU

I mean… they get terminated somehow, right?

True, but splicing without leaving behind a powered repeater is different from the final termination with active electronics on the end.

It's pretty cool tech

I’m saying you can terminate cleanly without needing a repeater.

To be clear, I’m saying to terminate each end of the cut cable to a terminating device that continues the flow of light, not just the termination at the beginning/end of the line. Sorry if that wasn’t obvious.

This is a great video on undersea cables https://www.youtube.com/watch?v=AFt9le2ytW0

"Sabatoge" and repair is discussed at 11:45

In this particular case, it seems like the attackers were trying for plausible deniability (making it look like an accident with an anchor). A comprehensive series of "accidents" wouldn't fit that goal.

(And if they decide they don't care about plausible deniability, they could use sub-deployed timed mines to take out every cable at once.)

Even if these "accidents" are a state sponsored (or at least condoned) action, it seems certain states have realized they can happen over and over again without consequences[0].

The frustrating part of this kind of petty tactic is that bullies can do just enough to annoy and inconvenience their targets, while never quite doing enough to make it worth expending the political capital to hold them to account. From the bully's perspective there's no downside. And if legitimate accidents or rogue actions get portrayed as deliberate then all the better - that just reinforces the bully's reputation as an actor to be feared while further eroding trust in the international institutions that may one day challenge it.

[0] https://www.taiwannews.com.tw/news/5677668

And then once they are fixed take them out again

> once they are fixed take them out again

In an actual war, you hit the repair equipment and personnel [1].

(As to the Geneva Conventions note, we're discussing a hypothetical war with Russia. The status quo, including rules of war, are going to be rewritten by the victors.)

[1] https://en.wikipedia.org/wiki/Double_tap_strike

Shhh, or somebody will realize how much slack there is in the system (for very good reasons, as evidenced here) and "optimize" it away...

Can anyone explain why there wasn't any BGP activity on the Finland-Germany systems when the cable broke, while for Lithuania there was a massive spike?

Unfortunately it's been a long time since I learned about BGP, if anyone could help out here I'd be grateful.

Each BGP hop represents an ISP so when an ISP reroutes traffic internally there's no need for changes to external BGP announcements. Clearly ISPs in the Baltic region have multiple paths and don't depend on any one cable.