Putin has a huge advantage in the kind of nuclear weapon he would be most likely to use

Russian President Vladimir Putin chairs a Russian Security Council meeting at the Novo-Ogaryovo residence outside Moscow on March 3. (Andrei Gorshkov, Sputnik, Kremlin Pool via AP)

Vladimir Putin’s brandishing of his nuclear arsenal could hardly be less subtle if Russian TV broadcast him driving a mobile intercontinental ballistic missile launcher through Red Square. He began his invasion of Ukraine less than a week after personally overseeing a Russian nuclear exercise and on Sunday ordered his nuclear forces on high alert. In case the message was lost on anyone, Russian Foreign Minister Sergei Lavrov on Wednesday vowed that if World War III comes, it will be a nuclear conflict.

But a nuclear conflict won’t necessarily be World War III — and that could be to the Russians’ advantage. If Putin ever does go nuclear, he is more likely to authorize a limited use of smaller, “nonstrategic” nuclear weapons, whether in desperation if his Ukraine invasion continues to sour, or against NATO countries in some future confrontation.

Such non-strategic, or tactical, nukes might not end the world, but they could end a battle — or even a war — by taking out the 160 tanks in an armored division, for example. Russia could be emboldened to take such a step because it has more tactical nuclear weapons than all of its rivals, including the United States. This imbalance deserves immediate American attention.

Russia has only a modest lead over the United States in long-range, strategic nuclear warheads regulated by the 2010 New Start treaty — 1,456 vs. 1,357 of the high-payload weapons. But when it comes to unregulated, shorter-range and lower-payload tactical nuclear weapons, according to a 2021 Congressional Research Service report, the United States has only 230, “with around 100 deployed with aircraft in Europe.” Russia has up to 2,000.

Four years ago, the Trump administration’s Nuclear Posture Review presciently raised the prospect that in a conflict near Russia’s borders, Moscow might “rely on threats of limited nuclear first use, or actual first use, to coerce us, our allies, and partners into terminating a conflict on terms favorable to Russia.”

While Russia might lose a conventional war with NATO, the thinking goes — and all sides would lose a full-fledged nuclear war — Moscow’s use of one or a handful of nonstrategic nuclear weapons against military targets would move the conflict into a realm Russia is equipped to dominate.

Wouldn’t Russia be deterred from crossing that line in Europe by the prospect of mutually assured destruction? Maybe, but the notion that Washington would escalate to strategic nuclear weapons in the absence of an imminent threat to the homeland “is just too extreme to be convincing and therefore unlikely to work” as a deterrent, conservative strategist Elbridge Colby wrote in Foreign Affairs in 2018. He argued that if Russia crossed the nuclear threshold with a low-yield weapon against a NATO state, the United States would need to “respond in kind or risk defeat.”

Yet Russia’s nonstrategic nuclear weapons are not only more numerous but also more versatile than America’s, many of which can be delivered only from the air (making their credibility partly dependent on Western air superiority). Russia is building an arsenal including not just ground-to-ground missiles but also “antiship and antisubmarine missiles, torpedoes, and depth charges,” according to 2019 congressional testimony from the director of the Defense Intelligence Agency. Last weekend, Russia fired conventionally armed Iskander missiles, which can also be armed with nuclear warheads, into Ukraine from Belarus.

The Biden administration is contemplating policies that could widen Russia’s nonstrategic nuclear advantage. The Interim National Security Strategic Guidance last March promised to “reduce the role of nuclear weapons in our national security strategy.” Some members of Congress and U.S. allies worry that the Pentagon will adopt a “declaratory policy” that narrows the circumstances in which the United States reserves the right to use nuclear weapons. Politico reported in January that the Nuclear Posture Review might also seek to retire the W76-2, a low-yield nuclear weapon that was first deployed in 2019 on an American submarine and is intended as a partial answer to Russia’s nonstrategic force.

The war in Ukraine could be an opportunity for the handful of hardheaded strategists in the Biden administration to prevail against the arms-control idealists, who believe that, given the destructiveness of these weapons, a quantitative advantage provides little practical edge. But nuclear deterrence is about perception and will. Arms-control advocates have long maintained U.S disarmament would be met with Russian reciprocity, but that faith is badly undermined by Moscow’s nuclear threats amid the fighting in Ukraine.

Western technological prowess and financial wizardry are building a virtual blockade around the Kremlin without the direct threat of military force. But the real world is ultimately the strategic backdrop for this and every armed conflict, and the tools of the information revolution can’t increase nuclear deterrence. Putin knows this. To deflate the Kremlin’s threats, the United States will need the weapons necessary to make Putin worry that even on a “limited” nuclear battlefield, he’d lose.