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The U.S. has begun production of a new nuclear weapon. Supporters of the weapon say it's needed to counter Russia, but critics worry it's taking America back to a time when nuclear weapons were more likely to be used. NPR's Geoff Brumfiel has more.
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GEOFF BRUMFIEL, BYLINE: It wasn't that long ago when the military had plans to use nuclear weapons all over the place.
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UNIDENTIFIED PERSON: July 1962. These troops were the first in our Army's history to engage in a tactical exercise supported by live nuclear firepower.
BRUMFIEL: That's archival footage from the Nevada desert. Hundreds of troops rehearsed an attack, but before they went in, they fired a tiny nuclear weapon at a simulated enemy position.
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UNIDENTIFIED PERSON: It detonated perfectly, releasing its lethal radiation.
BRUMFIEL: Back then, that was how some thought nuclear war would look - nukes small enough to knock out just a couple of city blocks used together with conventional weapons like tanks and troops. Of course, that's not what happened. Radiation and other factors made nuclear weapons a bad fit for the battlefield. And as the U.S.'s conventional strength grew, battlefield nuclear weapons became less important.
MATTHEW KROENIG: And at the end of the Cold War, the United States said, well, that was kind of stupid. Why did we have all this stuff? Let's get rid of it.
BRUMFIEL: Matthew Kroenig is at the Atlantic Council. He also worked on nuclear strategy in the Pentagon. The U.S. dismantled nearly all of its battlefield nuclear weapons, but Russia took a different path. It has kept thousands of battlefield nukes in storage.
KROENIG: So today, Russia has nuclear landmines, nuclear torpedoes, nuclear depth charges, nuclear artillery, nuclear short-range missiles.
BRUMFIEL: And the Trump administration believes Russia would be tempted to use some of these weapons in a conflict. If that happened, Kroenig says, the U.S. wouldn't be able to respond in kind. The only nukes it has left are big weapons designed to fight an apocalyptic nuclear war. So the administration has begun converting an existing larger warhead into a new smaller low-yield weapon more like the old battlefield nukes.
KROENIG: What the low-yield nuclear weapons do is say, no, actually, we have a range of options. If you use a low-yield nuclear weapon, we can respond with one, two or three of our own.
JEFFREY LEWIS: I mean, well, it's insane.
BRUMFIEL: That's Jeffrey Lewis, a scholar at the Middlebury Institute of International Studies, who's not a fan of battlefield nukes. The Trump administration's new warhead sits on the same missile that now carries a much more powerful nuclear weapon. So if the U.S. did use it for some reason...
LEWIS: All the Russians are going to see is that a missile that only carries nuclear warheads is heading toward Russia. And Russian policy, as Vladimir Putin has said many times, is not to wait for it to land.
BRUMFIEL: In other words, Russia could unleash an attack on the U.S. just to be safe. Olga Oliker is with the International Crisis Group. She says just the existence of smaller U.S. weapons could cause the Russians to take battlefield nukes out of storage.
OLGA OLIKER: They think, wow, we need to deter that. No way our conventional weapons deter that. We have to emphasize the nuclear capability.
BRUMFIEL: She says that could end up countering the vastly superior conventional forces of the U.S.
OLIKER: They're throwing away an advantage.
BRUMFIEL: The Trump administration says several of these new smaller weapons will be ready to enter service later this year, but the administration's long-term plans for more battlefield nukes face a bigger obstacle - newly elected Democrats have vowed to block them. Geoff Brumfiel, NPR News, Washington.