JON WOLFSTHAL:

Well, if you believe that, then you would like the fact that we already have about 500 to 1,000 low-yield nuclear weapons in the arsenal. The air-launched cruise missile and the B-61 bomb in Europe both have lower yields.

But I think it also ignores the fact that Russia is threatening the use of nuclear weapons because they're conventionally inferior to the United States. They have no choice but to threaten nuclear weapons because they know that they would lose a conventional war to NATO or the U.S., which is the same thing we threatened during the '60s, that we would escalate to the nuclear use and response to a conventional attack.

So, I understand the desire to deter. And I think it's an important one. And the language in the NPR on deterrence I think is sound. The problem is that Russia is going to look at these new capabilities, and they're not going to change their strategy. They are going to say, all right, well, they're going to beat us conventionally and they can beat us on the nuclear front, so we need to take even more asymmetric steps.

And I think that is going to increase the risk of misinterpretation or accident.