Our colleagues from Estonia explained to us how devastating a cyber-attack can be, because they're so heavily dependent on modern technology. It can just close everything down, from getting money out of bank machines to the lights. Everything stops. There is research on that. NATO was involved with research on cyber up in Estonia and the Balkans, which we all participate in and have a chance to learn from.
On February 8th, 2018. See this statement in context.