Nuclear Weapons Are Getting Less Predictable, and More Dangerous
Facing steerable ICBMs and smaller warheads, the Pentagon seeks better tracking as the White House pursues an unlikely arms-control treaty.
On Tuesday, U.S. Secretary of State Mike Pompeo met his counterpart, Russian Foreign Minister Sergey Lavrov, to discuss, among many things, the prospect of a new, comprehensive nuclear-weapons treaty with Russia and China. At the same time, the Pentagon is developing a new generation of nuclear weapons to keep up with cutting-edge missiles and warheads coming out of Moscow. If the administration fails in its ambitious renegotiation, the world is headed toward a new era of heightened nuclear tension not seen in decades.
That’s because these new weapons are eroding the idea of nuclear predictability.
Since the dawn of the nuclear era, the concept of the nuclear triad — bombers, submarines, and intercontinental ballistic missiles — created a shared set of expectations around what the start of a nuclear war would look like. If you were in NORAD's Cheyenne Mountain Complex in Colorado and you saw ICBMs headed toward the United States, you knew that a nuclear first strike was underway. The Soviets had a similar set of expectations, and this shared understanding created the delicate balance of deterrence — a balance that is becoming unsettled.
Start with Russia’s plans for new, more-maneuverable ICBMs. Such weapons have loosely been dubbed “hypersonic weapons” — something of a misnomer because all intercontinental ballistic missiles travel at hypersonic speeds of five or more times the speed of sound — and they create new problems for America’s defenders.
“As I stand here today, I don’t know what that solution set looks like,” Gen. Paul Selva, the Vice Chairman of the Joint Chiefs of Staff, said at an Air Force Association event in April. “If you’re going Mach 13 at the very northern edge of Hudson Bay, you have enough residual velocity to hit all 48 of the continential United States and all of Alaska. You can choose [to] point it left or right, and hit Maine or Alaska, or you can hit San Diego or Key West. That’s a monstrous problem.”
This makes it harder for U.S. leaders, in the crucial minutes before a potentially civilization-ending nuclear strike, to understand just what kind of weapon is inbound.
“Our indications and warnings today are based on modestly maneuvering reentry vehicles that have a ballistic trajectory until the warhead leaves the missile,” Selva said. They basically consist of a heat bloom “that tells you, ‘You are under attack,’ and one radar hit that tells you where the ballistic trajectory is going.”
Those two data points give a “reasonable probability” of predicting where a conventional ICBMs will land, he said. “That gives us some assurance that we can provide a nuclear command and control structure that has enough decision time in it to react if we’re under massive attack or to make a decision not to react if we’re not. Hypersonics begin to tear apart that indicators-and-warning system.”
So Pentagon officials are looking to launch a new network of low-Earth-orbit satellites that can better track maneuvering intercontinental missiles. (They are also developing hypersonic weapons of their own; some ground-based engine tests are slated for later this year.)
Another wildcard is the future of variable- or low-yield nuclear weapons. Russia has perhaps 2,500 of these smaller nukes, according to Hans M. Kristensen of the Federation of American Scientists. Russian doctrine contemplates using mini-nukes to secure tactical victory on an otherwise conventional battlefield, reasoning that the United States would be unwilling to strike back with a much larger weapon that might, say, also destroy a nearby city. The Pentagon calls this the “escalate to de-escalate” doctrine.
The United States is starting to build a new generation of smaller nukes of its own. The reasoning was laid out in the 2018 Nuclear Posture Review, and the weapons have been rolling off the assembly line since January.
“A limited number of low-yield nuclear weapons provides the president with an option where we can say, ‘If the Russians attacked us with a low-yield nuclear weapon, we have an option to reply in kind that is inherently de-escalatory and stabilizing’,” Selva said.
But Selva also noted that low-yield weapons present the same sort of ambiguity as hypersonic weapons.
“We don’t know what they launched at us until it explodes,” he said.
The U.S. military has responded to Russian weapons development with several other key moves: building a next-generation air-launched cruise missile, hiring Northrop Grumman to build a new penetrating bomber, lowering the nuclear yield on some sub-launched ballistic missiles, and exploring bringing back a sea-launched cruise missile, or SLCM, that could have a nuclear tip.
“This suite of systems will provide capabilities that enable the United States to threaten limited response options of varying sizes against targets throughout Russia and, if needed, against deployed Russian forces,” according to a March report from the Center for Naval Analysis, or CNA.
A senior Defense Department official said a new SLCM might add to the nation’s arsenal of low-yield nukes, or simply replace current warheads if arms-control agreements require.
Warhead numbers are less important than they used to be. The U.S. isn’t interested in matching Russia’s number of small-yield bombs. It doesn’t have to. One of the benefits of having lots of ambiguous weapons is that all of your missiles and bombs become a bit more threatening.
“They have many more than we do, that’s true,” said Selva of the low-yield nuclear bombs. “But we now have a way to answer that threat. It’s important to have that as part of our option set.”
Lynn Rusten, vice president of the Global Nuclear Policy Program at the Nuclear Threat Initiative, said that the ambiguity problem would apply to the SLCMs effort as well. “We use conventional SLCMs a lot in our normal warfare. If you start having nuclear SLCMs deployed as well, there will be a real discrimination in terms of when one of those things is launched, what is that thing coming at you? Where is it going?”
As new weapons inject new uncertainty into nuclear strategy, the Trump administration’s main responses have been to tear up one arms-control treaty, remain non-committal on extending another, and to propose a third: a new, comprehensive nuclear-weapons agreement between China, Russia, and the United States.
After his Tuesday meeting with Lavrov, Pompeo said Trump had “charged his national security team to think more broadly about arms control, to include countries beyond our traditional U.S.-Russia framework and a broader range of weapon systems. The president wants serious arms control that delivers real security to the American people. And we know – and I think we agree on this – to achieve these goals, we’ll have to work together, and that it would be important that, if it’s possible, we get China involved as well.”
But experts say Beijing has no interest in such an agreement. For one thing, its nuclear arsenal is far smaller than the U.S. and Russian ones — though it has recently developed a ballistic-missile submarine fleet and is outpacing the United States in hypersonics.
“China’s longstanding policy is that it will join the process once Washington and Moscow have completed deep and irreversible reductions and foresworn the right to use nuclear weapons first,” the CNA report said.
The report also notes that Beijing would be reluctant to submit to the kind of transparency and verification arrangements that make arms-control treaties work.
“In China’s policy, opacity makes a major contribution to the survivability of its smaller nuclear force. Chinese policy statements often assert that the United States, as the stronger power, has an obligation to be transparent about its capability, while China is entitled to opacity because disclosing more detailed information about the size, composition, geographic locations, and planned trajectory of its nuclear posture would create operational vulnerabilities,” it said
Many arms control experts say the first and most important step that the U.S. could take in navigating this far more unpredictable future is to extend New START. Even Selva, who declined to offer a public recommendation about such an extension, said that the United States benefits in multiple ways from the treaty’s mechanisms for keeping track of the parties’ strategic arsenals. “The treaty is what the treaty is. Does the extension of the treaty accrue to our national interest? That’s the only question we should ask. If we choose not to extend the treaty we live in a world without an accountable set of numbers. Does that accrue to our national interest? That is the way I believe we should have this debate,” he said.
The CNA paper goes further, saying that the treaty is a bulwark against inefficiency, ignorance, and ultimately, unpredictability.
“Without New START’s cooperative transparency practices, the U.S. intelligence community would likely devote more resources to monitoring Russian strategic nuclear forces but have less insight and less confidence in its analytical judgements,” it said. “The United States would face an opportunity cost of diverting scarce national technical means (NTM), such as satellites, and technical analysts from other missions. Russian defense officials would also navigate increased uncertainty and lose the ability to confirm that the United States has not reversed its New START reductions. Neither country would have the same degree of confidence in its ability to assess the other’s precise warhead levels. Worst-case scenario planning is also more likely as a result.”
The administration’s internal policy debate has begun to anger some lawmakers. On Wednesday, the Senate Foreign Relations Committee heard testimony from Undersecretary of State for Arms Control and International Security Andrea L. Thompson. She said renewing New START might not be in the best interests of the country, and that the administration was looking at it. But she declined to elaborate.
So Sen. Bob Menendez, D-N.J., asked her, “If New START expires could Russia target the United States with hundreds or possibly thousands of additional nuclear warheads?”
Thompson responded that that was a good question for Russia but she wasn’t going to answer hypothetical questions.
Menendez exploded. “It’s not a hypothetical. It’s what would happen if we cannot verify what they’re doing.”
A collapse of New START might also cause China to embrace a more aggressive nuclear stance to hedge against rising unpredictability.
Tong Zhao, a fellow in Carnegie’s Nuclear Policy Program at the Carnegie–Tsinghua Center for Global Policy, wrote that the treaty’s end could “increase Chinese uncertainty about the sizes of U.S. and Russian strategic nuclear arsenals and so exacerbate China’s concerns about their numerical growth. Second, a lack of transparency would lead the U.S. and Russian arsenals to grow faster than they otherwise would, and lead China to attribute such growth to more aggressive intentions of the two big nuclear powers.”
As uncertainty increases, misperceptions become more dangerous. And there is reason to believe the United States is already looking at the situation through various imperfect lenses. One is the belief that China has any interest in trilateral arms control. Another is “escalate to de-escalate.” Some Russia experts, such as Olga Oliker, the Europe and Central Asia director at the International Crisis Group, call it a fiction dreamed up in the West after a misreading of a Russia’s 2017 Naval Doctrine.
“Moscow continues to believe, and Russian generals in private conversations emphasize, that any conventional conflict with NATO risks rapid escalation without ‘de-escalation’ — into all-destroying nuclear war. It must therefore be avoided at all costs,” she wrote in February.
“If anything, U.S. emphasis on new lower-yield capabilities — effectively an ‘escalate to de-escalate’ strategy of the sort many attribute to Russia — would undermine the deterrent balance, potentially triggering the very sorts of crises low-yield proponents hope to avert.”
Michael Kofman, a senior research scientist at CNA, says the “escalate to de-escalate” debate obscures a more fundamental truth about Russian strategic doctrine. “Russia has never accepted the proposition that a war with the United States could be conventional only. Hence, Russian nuclear strategy has a firm place for scalable employment of nuclear weapons, for demonstration, escalation management, warfighting, and war termination if need be,” he told Defense One. “The gist of the problem is that the Pentagon believes that nuclear weapons are some kind of gimmick that can be deterred in conventional war, but actually the prospect for conventional-only war with Russia is somewhat limited from the outset.”
Bottom line: the U.S., Russia, and China, may be entering into a high-stakes discussion on nuclear arms with each suffering from severe misconceptions about the others’ intent. The price of failure of the new negotiation effort, if New START is not re-affirmed, would be a new period of heightened nuclear tensions and less predictability.
Rusten believes the arms race has already begun.
“We don’t want to be where that trajectory will take us five years from now,” she said.