Why Russia’s Tactical Nuclear Weapons Are Key to Its Defense Strategy

The veiled threats that they could be used in Ukraine have been a factor in limiting the direct involvement of North Atlantic Treaty Organization members in the conflict, despite doubts among many Western analysts that breaking a taboo against nuclear weapons use that has held for more than 75 years would benefit Moscow in the fight.

“Nonstrategic nuclear weapons are a game changer for them,” said Christopher Yeaw, a specialist in nuclear deterrence at the National Strategic Research Institute at the University of Nebraska. Moscow has pursued development of these weapons “with rigor,” he said.

Their importance to Mr. Putin has been shown by announcing the proposed deployment of such weapons to Belarus last month. The announcement directly contradicts a joint statement he made just a few days earlier with Chinese leader

Xi Jinping,

by far Mr. Putin’s most important partner, that declared “all nuclear weapons states should refrain from deploying nuclear weapons abroad.”

Tactical nuclear weapons are short-range weapons designed for use in the battlefield or to take out critical infrastructure, such as power stations. Unlike strategic nuclear weapons—a weapon of last resort designed for the destruction of large cities—tactical nuclear weapons have never been constrained by any formal arms-control agreement.

“The nonstrategic weapons in the Russian arsenal are among the most obscure or opaque facts simply because they have never been regulated in a verified agreement,” said Hans Kristensen, director of the Nuclear Information Project at the Federation of American Scientists.

This has contributed to a lack of clarity about how many such weapons Moscow has in contrast with strategic nuclear arms, numbers of which have until recently been declared and verified by the U.S. and Russia. There is also a range of qualitative assessments in the West about what types of weapons Moscow has developed.

Western estimates vary from fewer than 2,000 tactical weapons from Mr. Kristensen and colleagues to double or more that figure. By contrast, the U.S. has 230 B61 tactical nuclear bombs now being modernized—an estimated 100 of which are in Europe and designed to be carried by the air forces of NATO allies Belgium, Germany, Italy, the Netherlands and Turkey. It also has two other nuclear warheads, launchable on missiles from submarines or aircraft, that can be dialed back to deliver a reduced explosive force.

Mr. Putin referred to the shared weapons when he said there was “nothing unusual” about deploying nuclear weapons to Belarus. “The United States has been doing this for decades,” he said. “They have long deployed their tactical nuclear weapons on the territory of their allied countries, NATO countries, in Europe.”

In contrast to the U.S., Russia has dozens of systems capable of delivering a nuclear warhead, from sea, subsea, land, air and from coastal- and air-defense forces. Many of these systems have been used to deliver conventional warheads in the war in Ukraine.

Some analysts, including Dr. Yeaw, say that Russia has been developing tactical weapons that focus on nonexplosive effects, such as the electromagnetic pulse generated by nuclear explosions that knock out electrical systems, and weapons with reduced nuclear fallout.

They also say Moscow has developed warheads with capabilities ranging upward from what his institute defines as “ultra low-yield” weapons from as little as 10 tons of TNT-equivalent explosive force to very low-yield weapons running into the hundreds of tons.

For comparison, the nuclear bomb dropped at Hiroshima delivered 15,000 tons of explosive power, and the yield of the August 2022 explosion in Beirut was about 300 tons. The biggest conventional weapon developed by the U.S.—the so-called Mother of all Bombs used in Afghanistan in 2017—and also likely by Russia are in the order of 10 tons. But delivering these conventional bombs would require a large and vulnerable heavy strategic bomber.

Arms-control specialists say that if Russia has developed these capabilities, it could further lower the bar against nuclear-weapons use. But while there is agreement that Russia has emphasized tactical-weapons development, many analysts say they just don’t know how far that development has really gone.

Valeriy Akimenko, a Russian nuclear-weapons specialist at the Conflict Studies Research Centre, a U.K. think tank focused on Eurasia, said Russia has “a numerically substantial and typologically varied arsenal that is little understood, that is outside of international control and that imparts Russia with, in theory, a significant advantage over the United States in that particular weapons category.”

The gap between Russian and U.S. capabilities has led U.S. lawmakers to call for tactical weapons to be included in future arms-control negotiations. But even strategic arms control is under threat after Mr. Putin suspended application of the New Start treaty that expires in 2026. The absence of China in any arms-control agreement is further diminishing hopes that a replacement will be negotiable.

The differential in capabilities has also led some nuclear-weapons experts to identify a gap in what they call the escalatory ladder. This means the U.S. wouldn’t be able to respond in kind to Russia’s use of a small tactical nuclear weapon because it is incapable of delivering a like response without severely escalating the conflict. The logic is that the U.S. needs to develop further tactical capabilities so that it can match Russia’s.

Some arms-control specialists disagree, saying the U.S. has the superiority in conventional arms to enable it to respond adequately to tactical nuclear-weapons use. They say it is illogical to argue that Russia’s deployment of tactical weapons risks escalating the arms race but that the U.S.’s doesn’t.

Mr. Kristensen says the escalation gap argument is “old fashioned.”

“It’s not like we woke up in 2014, and 2021, or 2022, and then decided, ‘Oh, my God, the Russians have built all these tactical nuclear weapons.’ We’ve been fully aware of this for the last three decades.” The U.S. military has decided to rely not on tactical nuclear weapons but long-range and “nonnuclear systems that we can actually use.”

Experts say that NATO’s superiority in conventional arms has worried Moscow since the end of the Cold War and hasn’t diminished. Russia’s poor military performance and the loss of its best equipment and men in the last 13 months has likely reinforced that assessment.

Moscow is particularly concerned, said Dr. Yeaw, about U.S. stealth technology that makes its fifth-generation aircraft, now also being used by American allies, hard to identify by Russian air defenses. That makes NATO air bases, typically not hardened targets, a likely primary objective of Russian tactical nuclear strikes in any future conflict.

One question, given the evidence of poor maintenance of Russian equipment in Ukraine, is whether Russian military commanders would be confident in using tactical nuclear weapons. William Alberque, a former director of NATO’s weapons of mass destruction nonproliferation center now with the International Institute for Strategic Studies, said confidence might not be high that the systems would work. Given the likely international reaction to breaking the taboo on nuclear-weapons use, Russian commanders might be reluctant to “fire and hope.”

This uncertainty would mean it is unlikely that Russia would use one or two of such weapons and would need to use many more, increasing the prospects that their movement from storage facilities would be detected by U.S. satellites.

People have argued, he said, that the Russians might “just sneak one warhead out of one of their storage facilities…That’s absurd because what if the motor fails, what if the warhead fails?”

Some U.S. experts, including some who have visited Russian nuclear facilities, say there may be doubts about the reliability of some Russian delivery systems such as missiles. However, they say the Russian defense establishment treats its nuclear warheads with care that has, on the evidence of the Ukraine war, been denied to much of the rest of the military.

Russia’s nuclear warheads are managed by what Russia calls the 12th Main Directorate, an elite military force given priority by the Russian military.

William Moon, now an independent consultant and a former program manager at the Defense Threat Reduction Agency, visited Russian facilities run by the 12th Main Directorate under the Cooperative Threat Reduction nuclear-security program until Moscow’s cooperation was suspended after the annexation of Crimea in 2014.

The directorate—at least until 2013—“was on another scale in terms of the quality of their people” compared with other military organizations, even elite ones such as Russia’s strategic rocket force, he said.

The directorate made no distinction between tactical and strategic warheads that were treated with equal care. “When we first started talking about, well, ‘are these tactical or strategic?’ they’re like, ‘No, that’s not how we think about it,’” he said.

Write to Stephen Fidler at [email protected]