ROBERT SIEGEL, HOST:
There is much confusion and some consternation today about Donald Trump's pronouncement on nuclear weapons. Yesterday in a tweet, the president-elect said this. (Reading) the United States must greatly strengthen and expand its nuclear capability until such time as the world comes to its senses regarding nukes.
It was unclear whether strengthening and expanding U.S. nuclear capability meant proceeding with the modernization of the nuclear arsenal that's underway or whether it meant something more than that. And then today on the MSNBC program "Morning Joe," hosts Mika Brzezinski and Joe Scarborough said that she had talked to Trump by phone.
(SOUNDBITE OF TV SHOW, "MORNING JOE")
JOE SCARBOROUGH: And the president-elect told you what?
MIKA BRZEZINSKI: Let it be an arms race. We will outmatch them at every pass.
SCARBOROUGH: And outlast them all.
BRZEZINSKI: And outlast them all.
SIEGEL: Well, do Donald Trump's words signal a shift on U.S. nuclear strategy? We're going to ask Dan Zak, whose book "Almighty" focused on nuclear weapons and their opponents. Welcome to the program.
DAN ZAK: Thank you, Robert.
SIEGEL: What do you make of Donald Trump's comments about nuclear weapons?
ZAK: Well, I don't know. I mean I think without a - holding a proper press conference, we're left not to read tea leaves but tweet leaves. And there are many words in that one tweet that you can interpret.
He uses verbs like strengthen and expand. And does that mean, as you said, that he's endorsing this $1 trillion modernization of our nuclear forces, which is already underway? Or does he want to go against decades of policy limiting and reducing the number of weapons.
SIEGEL: Put this in the context of what Trump said about nuclear weapons during the campaign or what his campaign said for that matter.
ZAK: Well, he was a bit inconsistent. Trump said, you know, he'd be the last to use nuclear weapons. Nuclear weapons are a horror. He seemed to understand what they're capable of doing.
At the same time, he said it was only a matter of time until countries like South Korea and Japan get nuclear weapons. He seemed to tacitly or not so tacitly endorse proliferation, again going against decades of international policy.
SIEGEL: How much would you say his ideas are a shift from recent or historic attitudes toward nuclear weapons?
ZAK: I mean we've reduced - the U.S. has reduced its volume of warheads virtually every year since 1967. We had 31,000 in the active stockpile. We have between 4,000 and 5,000 now. By expanding, does he mean add to that? By expanding, does he mean expand the capabilities of that?
I mean it's the stated policy of the Obama White House that there will be no new capabilities, no new warheads, and we will reduce the role of nuclear weapons in national security strategy. So that seems to go against not only historical precedent but the Obama administration's stated policy.
SIEGEL: Donald Trump did say some things before this most recent tweet about nuclear weapons along the lines of - what's the big deal about nuclear weapons; what's so different about them? That statement is out of line with what presidents. Even regardless of what they did, it's out of line with what presidents have said about nuclear weapons.
ZAK: Right, I mean presidents going back to Truman have been very careful about their public statements about these weapons. You have Eisenhower saying you can't have a nuclear war; there aren't enough bulldozers to scrape the bodies off the street. You had Ronald Reagan say, a nuclear war cannot be won and must never be fought. You have President Obama saying, we must seek the peace and security of a world without nuclear weapons.
Each of those presidents has presided over either some kind of buildup or some kind of reinvestment in the nuclear arsenal, but they still were very careful about what they said in public. This tweet of Donald Trump's is kind of - I think breaks precedent with that. And so it remains to be seen exactly what he meant and exactly what kind of effect, if any, it will have.
SIEGEL: Did you hear the sound of a lot of heads being scratched today after...
ZAK: Well...
SIEGEL: ...After these remarks?
ZAK: Yeah, not only heads being scratched but people talking about how nuclear annihilation is around the corner, that this is it, that a new arms race is underway. And I think that a modicum of concern or even of hysteria is warranted. These are devices that could end civilization.
At the same time, you could argue that an arms race is already underway. We're spending a trillion dollars to modernize. And it may not be an arms race in terms of number of weapons, but it could be interpreted as an arms race in terms of capabilities. Like with a lot of things the president-elect has said, there is opportunity to overreact, but it also kind of shines a light on a topic or a truth that we all should be talking about more.
SIEGEL: Dan Zak, author of the book "Almighty," thanks.
ZAK: Thank you, Robert. Transcript provided by NPR, Copyright NPR.