In a call with Virginia regional media today, Virginia U.S. Sen. Mark Warner said Putin’s threat of cyberwarfare factors adding to his invasion of Ukraine could lead to an escalation that may advance beyond a level even he, as a cyber expert in the U.S. Senate, can predict. When it comes to “cyber escalation,” he said, “I don’t know what that looks like.”

He said he’s surprised that Putin has apparently shown restraint in the use of cyber attacks to date, and is not sure why. But he said he’s confident the U.S. is “resilient” and well prepared to handle efforts to “take down our banking system, for example.”

He said he “favors a forward deployment of U.S. troops” in Europe, currently being discussed, where the U.S. has a total of 100,000 troops.