Russian crew detained after undersea cable cut in 'sabotage'

BCS Phase II connects Russia through Finland [1]. What would be the consequences to Russia if it were turned off?

(I suppose one could also drag an anchor across this guy [2].)

[1] https://www.submarinecablemap.com/submarine-cable/bcs-north-...

[2] https://www.submarinecablemap.com/submarine-cable/kingisepp-...