NATO has confirmed it now considers cyberspace to be a potential front line in conflict, with members of the military alliance pledging to boost IT security spending and information sharing.
The announcement was widely expected but is the second update to NATO's cyber defence strategy in two years, as the alliance has gradually worked out how to deal with a new threat landscape, which now includes state-backed hackers and attacks on the systems controlling critical infrastructure alongside tanks and rockets.
NATO Secretary General Jens Stoltenberg said that defining cyberspace as an "operational domain" alongside land, air, and sea would mean better protection of its networks, missions, and operations.
"NATO's cyber posture remains defensive," he said. "But this is a clear sign that we are strengthening our collective defence in all areas. Allies have also pledged to strengthen their own cyber defences, and share more information and best practices."
He added: "NATO's security depends on all our nations being prepared. So today, allies committed to boosting their resilience, to improve civil preparedness, and ensure we have the right mix of capabilities to meet new challenges, including hybrid warfare."
NATO's "cyber defence pledge" sees members of the alliance promising "in recognition of the new realities of security threats to NATO" to be capable of defending themselves in cyberspace as in the air, on land, and at sea.
Members said they will bolster the cyber defences of national infrastructures and networks: "Our interconnectedness means that we are only as strong as our weakest link. We will work together to better protect our networks and thereby contribute to the success of allied operations."
The document pledges members of the alliance to strengthen the security of national networks and infrastructures "as a matter of priority". This would include:
NATO said in order to track progress on the delivery of this, an annual assessment "based on agreed metrics" will take place, and progress will be reviewed at the next NATO summit.
It's not clear what impact this pledge will have, as questions remain about the level of spending that some members will allocate to cyber defence, and NATO is vague about whether members would use digital weapons to strike back against aggressors. It also remains to be seen how other nations around the world are likely to respond to the alliance's new posture.