By Andrea Germanos

The chair of the Senate Intelligence Committee on Thursday elevated questions about whether a Russian cyberattack could trigger an Article 5 “collective defense” response from NATO and thus set off a broader war.

Sen. Mark Warner’s (D-Va.) comments to multiple news outlets come just after Russia launched a military attack on Ukraine and continued cyber attacks targeting Ukrainian government institutions.

Speaking on “CBS Mornings,” Warner referenced Russia’s 2017 “NotPetya” crippling cyberattack involving a single piece of malware and said a broader computer-based offensive by Moscow was certainly possible..

“If the Russians decide they’re going to turn off the power, turn off all the electricity all across Ukraine,” said Warner, that same attack could “very likely… turn off the power in eastern Poland, in eastern Romania.” That in turn could affect U.S. troops based in eastern Europe, for example, “if suddenly hospitals are shut down.”

In such a scenario, he continued, “we are suddenly in an area of hypothetically an Article 5 where one NATO country is attacked we all have to come to each other’s aid.”

Warner’s comments came the same day NATO Secretary-General Jens Stoltenberg called Russian’s attack on Ukraine “a brutal act of war” and lamented that “peace in our continent has been shattered. We now have war in Europe, on a scale and of a type we thought belong to history.”

“NATO is the strongest alliance in history, and make no mistake we will defend every ally against any attack on every inch of NATO territory,” said Stoltenberg. “An attack on one ally will trigger a response from the whole alliance.”

In 2020, NATO Deputy Secretary Mircea Geoana said at an annual policy conference in Poland that the leadership of the military alliance had “agreed that a cyberattack could trigger Article 5 of our founding treaty, where an attack against one ally is treated as an attack against all.”