Do American intelligence communities need to rethink secrecy when it comes to cyber warfare? It's something New York Times national security correspondent and best-selling author David Sanger suggests in his new book, "The Perfect Weapon: War, Sabotage, and Fear in the Cyber Age."

"The classifications surrounding cyber is one of the biggest reasons that we've got a continued threat. It's one of the first weapons that was ever developed by the intelligence community, and they're naturally secretive, and I understand that. And they don't want to reveal the ways they defend ourselves and do offense," Sanger said Friday on "CBS This Morning."

"But it gets into a big problem, and the big problem is that if you don't begin to talk about your capabilities, if you don't talk about what you may do in return, you've created no deterrence at all."

Sanger's book goes inside the rise of this new type of warfare and how cyberattacks are reshaping global power.

"In the years since the U.S. did the big attack on Iran's nuclear plan, called Stuxnet or Operation Olympic Games was the name for it, we have seen an explosion of cyber used by different states as a short-of-war way of attacking other nations. And the North Koreans are a great example of it. Because if you do this subtly enough, you can avoid retaliation. So they took out 70 percent of Sony Pictures' computer systems, but they got basically sanctions in return," Sanger said.

He was particularly struck, Sanger said, by how American presidents are "very concerned about striking back because of our continued vulnerabilities."

"The biggest example here was President Obama in trying to figure out how to deal with Vladimir Putin in the middle of the 2016 election," Sanger said. "Every time somebody would come to him with a proposal – and it's full of them here: cut off the Russians from the world financial system, go after Putin's own money. It's a, 'Well, what if he comes back on Election Day in the election machines?' Which they knew he was already probing."

Sanger writes that while the U.S. talks publicly about "setting norms" of what's off-limits for "offensive cyber activity" – including hospitals and election systems – the world sees America as "hypocrites."

"If we wanted to say election systems are off limits, we'd have to then commit that we're not going to attack someone else's elections systems. And believe it or not, there are people in the U.S. government who would raise objections to that," Sanger said.



Watch the video above to see what Sanger had to say about President Trump's historic summit with North Korean dictator Kim Jong Un.