How far will Putin go – and how far will America go to stop him?

Few Americans know more about cyber warfare, or Vladimir Putin, or how he may retaliate, than Alexander does: "He's not getting the movement out of the military in Ukraine.

I believe he's going to turn to cyber.

"I believe he's gonna hit Europe and the United States with that cyber.

We're gonna have to think that we're all part of this as well.

We can't just think of, it's the families of other people in America who've been deployed overseas and who have been in harm's way.

Koppel asked, "When you hear Vladimir Putin warning about consequences 'the likes of which the world has never seen before,' everybody immediately assumes that he's talking about nuclear warfare.

Could he be talking about cyber warfare?".

"I don't think there's any question he could be talking about cyber warfare," Panetta replied.

troops will be sent to Ukraine; at the same time, the president has warned Putin against attacking any one of the 30 nations which are part of NATO.

Koppel asked, "What's being posited right now, and this is not theoretical, this could be next week or next month, that Vladimir Putin orders Russian troops into one of those Baltic States.

Hill said, "[Putin] wants us to think and to believe, because he's been explicit about it, that the nuclear option is on the table.

And so, he wants us to know that he's thinking about his.

Because one of the things about Vladimir Putin, if he has an instrument, no matter how cruel and unusual or terrifying that instrument may be, he wants us to think that he would use it.

That's also a sign that he's playing

And I hope he's only playing, but [he's] playing a very, very dangerous game."

And I believe we're gonna push back in both those areas

The difference will be that I believe ours will be more focused to go after him than the Russian people."

Koppel asked, "The Russian people are accustomed to enduring pain.  The American people, quite frankly, are not

It'll awaken the American people, is my belief, and they'll say, 'This has to stop.' I don't know where that will go

I have tremendous faith and confidence in the will of the American people to push back when the going gets tough."