You answered part of the answer I was going to give. It's at the attribution issue.
The big challenge that we're facing in terms of cyber-attacks is that they are becoming increasingly sophisticated in hiding their footprint. We see, once again, that this is part of the methodology that those who attack through cyber are utilizing. You use small attacks, you see how quickly people are able to respond, and then you basically improve upon it. It's attack, learn, attack, learn. The attribution issue is going to be the problem.
I think that the way we would see a triggering of article 5 would be if we could somehow catch an attribution where it's clearly coming from a peer competitor—and I'm talking about the Russians in this particular context—and when it's something done to threaten the actual security system, in other words, bringing down the defence systems or intelligence systems, say, of the nuclear weapons of the United States or Britain or other parts of NATO. It would have to be very high. It would have to be a direct security threat and we would have to be in the stage where we already know how to respond to that cyber-attack before we can respond, because that's the added problem we face.