Sen. Mark Warner, D-Va., the ranking member of the Senate Intelligence Committee, says the United States and its allies are in a new Cold War with Russia that he calls a “shadow war” every bit as serious as the 20th-century struggle, but one using new indirect and amorphous tools and weapons.

America, Warner said Thursday, needs to bring this new war into the open and use all the new tools of technology to fight back hard.

“We are now engaged in a fight in the shadows and I’m not sure that’s a fight we’re currently winning,” he added.

Warner, whose committee is investigating Russian interference in the 2016 U.S. presidential election, said that the government has “done too little to respond to cyberattacks against us and our allies” and that America needs a new “deterrence doctrine so our adversaries don’t see such attacks against us as a free lunch.”

Too often, Warner said, the United States has responded quietly and on a “one-off” basis, and “that has not been enough to deter our adversaries.”