As part of its Nuclear Posture Review—the first since the 2010 review was completed—the Trump regime is said to be considering the building of a “mini-nuke,” a nuclear bomb with a low explosive yield. Advocates have long claimed this would improve U.S. deterrence. Approval of such a development would overturn the Obama administration’s policy of limiting reliance on nuclear arms and continuing to reduce the size of the U.S. nuclear arsenal.

Nuclear weapons tally

Bryan Bender at Politico reports:

"The [nuclear review] has to credibly ask the military what they need to deter enemies," added another official who supports such a proposal, particularly to confront Russia, which has raised the prominence of tactical nuclear weapons in its battle plans in recent years, including as a first-strike weapon. "Are [current weapons] going to be useful in all the scenarios we see?" [...]
"If the U.S. moves now to develop a new nuclear weapon, it will send exactly the wrong signal at a time when international efforts to discourage the spread of nuclear weapons are under severe challenge," said Steven Andreasen, a State Department official in the administrations of Ronald Reagan and George H.W. Bush who served as the director of arms control on the National Security Council in the Clinton administration. "If the world's greatest conventional and nuclear military power decides it cannot defend itself without new nuclear weapons, we will undermine our ability to prevent other nations from developing or enhancing their own nuclear capabilities and we will further deepen the divisions between the U.S. and other responsible countries.

Andreasen and other critics are right. 

The United States is already slated to spend $350 billion over the next decade to modernize its nuclear arsenal, both weapons and infrastructure. Including in this modernization the development of a generation of mini-nukes is a terrible idea.

For one thing—the main thing, really—it would increase the probability of nukes actually being used. And once the little ones are unleashed, what’s to stop the bigger ones from following in their trajectory? 

The 890 nuclear warheads currently deployed on U.S. submarines each have a yield of 7 to 30 times more power than the one dropped on Hiroshima in 1945. Although the actual toll will never be known for certain, that bomb killed around 80,000 people in a flash and at least another 100,000 from wounds and radiation-related sicknesses over the next 60 years. The fatalities from the bomb that took out Nagasaki were about half as many.

The horror of this alone gives pause to anyone except for the Dr. Strangeloves among us. However, decision-makers might be more willing to launch a nuke that yields, say, 10 percent of the Hiroshima bomb for use against a hard target such as, for instance, a deep underground weapons-manufacturing site in North Korea. In other words, advocacy of building new mini-nukes is accompanied by a doctrinal shift that makes a mini-nuclear war “thinkable.” The main trouble with such thinking? Once such a war starts, keeping it mini by confining it to the delivery of a few small nukes—or solely to the nation that’s been hit with them—may well be impossible. Delivering two or three of these to North Korea might very well spur the Chinese to respond with some bombs from their own nuclear arsenal. Nuclear calculus is a dicey game.

The idea of building low-yield nukes is hardly new. Before the major global reduction of nuclear warheads that began in the late 1960s, the U.S. had thousands of such mini-nukes in its inventory—artillery shells, land mines, depth charges, torpedoes, short-range ballistic missiles, even a kind of bazooka. 

It still has many nukes in the form of gravity bombs meant to be dropped from airplanes and warheads atop submarine-launched ballistic missiles and air-launched cruise missiles that can be instantly configured for low yields. Of a total active deployment of 1,740 bombs and warheads, the United States has several hundred with in-flight “dial-up” capabilities. This allows for variable yields as low as 0.3 kilotons of TNT (1/50th the yield of the Hiroshima bomb) and as high as 340 kilotons. 

At few months ago, James Doyle at the Bulletin for Atomic Scientists wrote:

In December [2016], the Defense Science Board—an independent group of experts and former officials that provides advice to the Defense Department—submitted a report advising the Pentagon to invest in low-yield nuclear weapons that could provide “a rapid, tailored nuclear option for limited use.” This recommendation struck a familiar note.

In 2003, the board issued a study entitled “Future Strategic Strike Forces” that suggested building small nuclear weapons with “great precision, deep penetration, [and] greatly reduced” yield and radioactivity. The board’s call led to investments in new warhead designs such as the Robust Nuclear Earth Penetrator—a warhead designed to destroy deeply buried or hardened targets including underground military command centers—and the Reliable Replacement Warhead. Both programs were cancelled in 2008, after millions of dollars had been spent.

Despite the board’s renewed interest in smaller nuclear weapons, and in weapons tailored for limited uses or specific effects, any effort to develop these weapons would encounter the same problem that earlier such efforts have encountered: It is impossible to determine if introducing weapons with these characteristics into the US stockpile, and planning for their use in certain scenarios, would strengthen deterrence or make nuclear war by miscalculation more likely. Building “mini” or tailored nuclear weapons might well lower the threshold to nuclear war; risking that outcome would only make sense if it were absolutely clear that introducing these weapons would remedy some dangerous weakness in deterrence.

Fortunately, no such weakness exists. Any nation using nuclear weapons against the United States or its allies risks a devastating response whose negative consequences would far outweigh any gains delivered by crossing the nuclear threshold. 

One key aspect of mini-nukes is their potential for use as first-strike weapons in internationally prohibited “preventive wars” that the Bush Doctrine posited. For instance, striking suspected or actual nuclear facilities in Iran or chemical weapons operations in Libya was one of the rationales for promoting development of low-yield nukes in the early 2000s. Such attacks might not develop into all-out war when directed against non-nuclear nations. But there are no guarantees and the potential for guessing wrong in this matter is enormous. 

Doyle continues:

Just as in the early 2000s, current proponents of mini-nukes or of vague “limited nuclear options” offer no convincing evidence that new weapons in this category are needed—or more importantly, that they would make nuclear use less likely. Instead, potential nuclear adversaries are likely to see the acquisition of additional weapons in this category as an indication that US opposition to nuclear use has decreased and that Washington may be the first to cross the nuclear threshold. Such an outcome would undermine global stability and increase the risk of nuclear war. Defense resources are better spent on strengthening US conventional forces.

And here’s Bender again:

"It is difficult to imagine the circumstances under which we would need a military option in between our formidable conventional capabilities and our current low-yield nuclear weapons capabilities," added Alexandra Bell, a former State Department arms control official. "Lawmakers should be very wary of any attempt to reduce the threshold for nuclear use. There is no such thing as a minor nuclear war."

There is a much-ignored part of the Nuclear Non-Proliferation Treaty—Article VI:

Each of the Parties to the Treaty undertakes to pursue negotiations in good faith on effective measures relating to cessation of the nuclear arms race at an early date and to nuclear disarmament, and on a treaty on general and complete disarmament under strict and effective international control.

That should be item No. 1 on the minds of the drafters of the latest Nuclear Posture Review, not the development and building of more nuclear weapons.

Ronald Reagan didn’t have the right idea about a lot of things. But he was right in pursuing "a world free of nuclear weapons," which he considered to be “totally irrational, totally inhumane, good for nothing but killing, possibly destructive of life on earth and civilization.” He and Soviet leader Mikhail Gorbachev put that vision on a path to reality with their disarmament negotiations. Barack Obama also wanted a world with zero nuclear weapons. Less than three months into his first term of office, he said in Prague: 

Some argue that the spread of these weapons cannot be stopped, cannot be checked — that we are destined to live in a world where more nations and more people possess the ultimate tools of destruction. Such fatalism is a deadly adversary, for if we believe that the spread of nuclear weapons is inevitable, then in some way we are admitting to ourselves that the use of nuclear weapons is inevitable.

Just as we stood for freedom in the 20th century, we must stand together for the right of people everywhere to live free from fear in the 21st century. And as nuclear power — as a nuclear power, as the only nuclear power to have used a nuclear weapon, the United States has a moral responsibility to act. We cannot succeed in this endeavor alone, but we can lead it, we can start it.

So today, I state clearly and with conviction America’s commitment to seek the peace and security of a world without nuclear weapons. I’m not naive. This goal will not be reached quickly — perhaps not in my lifetime. It will take patience and persistence. But now we, too, must ignore the voices who tell us that the world cannot change. We have to insist, “Yes, we can.” 

It’s true that most of the specific moves President Obama outlined in Prague toward global zero for nukes haven’t borne any fruit. But that doesn’t make his or President Reagan’s push in the no-nukes direction pollyannaish or in any other way wrongheaded. The last thing the man now in the White House should be doing is encouraging the building of more nuclear weapons based on the views of people who think deploying and using some small nukes would be valuable to U.S. security. He has a reputation for often ignoring advisers. He should definitely ignore the ones pushing this line.