Leaders of NATO member states agreed in 2014 that a cyberattack may unleash Article 5 of the North Atlantic Treaty setting out the fundamental principle of collective defence. Fifth Domain asked Luik during his recent visit to Washington whether any cyberattack has come close to launching Article 5.

"Some of the things which have happened are very serious," the Estonian minister told the portal. "Whether it would constitute an act of war, I think we have not risen to that level— yet."

Luik did, however, raise concerns about what dangers may already be planted in existing systems.

"One also has to keep in mind that, you know, there are news coming out often that bugs are found, for instance, in the electricity grid or in some other systems — this is all preparatory work," he noted.

"So if somebody wants to do something, then these are capabilities which are built over time to your system, so that at Point Zero, this can all be started very quickly," he added.

Like many other institutions, NATO faces the challenge of members who simply do not want to share much information about their cyber capabilities.

"When you talk to each other about the attacks, then you usually also relay your weaknesses — and you do not want everybody to know your weakness," Luik said. "So people are quite cautious, actually, in describing attacks to their system."

The upside, he noted, is that NATO has "found a good way of exchanging information in a very sound, confidential setting," which is helping to thaw the matter of information sharing among allies.

NATO capabilities come from member states

Luik also said that NATO is set for the near-term with how it handles cyber operations. He compared the current setup to the structure that has existed for decades with the alliance's nuclear capabilities, in which NATO acts as an organisational hub but national governments offer their own capabilities, Fifth Domain said.

"NATO itself does not have a big cyberdefence capability," he explained. "These capabilities come from state governments, and they can be used with the agreement of governments, especially the offensive capabilities. NATO does not have any offensive capabilities, but there are NATO countries who have considerable offensive capabilities."

The Estonian minister saw another parallel between cyber and nuclear.

"There has never been a real big cyberattack against another country which would utilise all the fearsome cyberweapons which are in the hands of many governments," Luik said. "People are cautious about it because that, you do it, it can be used against you as well. So there is actually this strange, strange balance of fear, not only of the nuclear issue, but also in cyber."