[The_Double]

This is one of the best, succinct lists of motivations for hybrid warfare i've seen.

But i could suggest another potential benefit for russia: If russia already operates under the assumption that they are in a (cold) war with EU/NATO, and they don't care about the effects on the relationship with Finland. Then this may simply be a really low cost, high damage operation. That not only imposes the replacement cost of the cable, but also forces countries to invest in counter measures.