Why the world is worried about Russia’s ‘tactical’ nuclear weapons

A bombed apartment building in the liberated of city Izyum, Ukraine, on Sept. 18. (Wojciech Grzedzinski/For The Washington Post)

The war in Ukraine has led to a resurgence of fears about the use of nuclear weapons. Russia is armed to the teeth with nukes, as are several of Kyiv’s Western backers.

If the conflict spiraled beyond Ukraine, it could pit nuclear powers against each other. Russian President Vladimir Putin made a clear reference to such a scenario in a national address last month that called for a partial military mobilization in the face of setbacks in the war.

“In the face of a threat to the territorial integrity of our country, to protect Russia and our people, we will certainly use all the means at our disposal,” Putin said. He and top officials have since echoed the sentiment.

For several months, the United States has been sending private communications to Moscow warning Russia’s leadership of the grave consequences that would follow the use of a nuclear weapon, according to U.S. officials. President Biden warned this week that the risk of nuclear “Armageddon” is higher than at any time since the Cuban missile crisis.

The strategic landscape has been complicated by the roughly 1,500 “tactical” warheads Russia has stockpiled since the Cold War ended. These smaller nuclear weapons, which are far less powerful than the ones the United States dropped on the Japanese cities of Hiroshima and Nagasaki during World War II, are designed to be used on the battlefield.

The smaller size of the weapons, some experts fear, could break down the nuclear taboo. They warn against underestimating what are still weapons of mass destruction, with the potential to cause widespread casualties from radiation alone.

Sarah Bidgood, director of the Eurasia program at the James Martin Center for Nonproliferation Studies in Monterey, Calif., said it was hard to estimate the level of risk that Russia would use a tactical nuke in Ukraine, but that it was clear that Russia relied on its nuclear weapons, including tactical weapons, to give it flexibility in managing the risk of escalation.

“Russia could introduce nuclear weapons into a conflict when it felt it had run out of conventional options and was facing an existential threat,” she said. But, she added, “we don’t have a good sense for what all of Putin’s red lines are here, or what he regards as an existential threat.”

Understanding the weapons that have drawn the world’s attention since Russia’s invasion of Ukraine

War in Ukraine: What you need to know

The latest: Russian President Vladimir Putin signed decrees Friday to annex four occupied regions of Ukraine, following staged referendums that were widely denounced as illegal. Follow our live updates here.

The response: The Biden administration on Friday announced a new round of sanctions on Russia, in response to the annexations, targeting government officials and family members, Russian and Belarusian military officials and defense procurement networks. President Volodymyr Zelensky also said Friday that Ukraine is applying for “accelerated ascension” into NATO, in an apparent answer to the annexations.

In Russia: Putin declared a military mobilization on Sept. 21 to call up as many as 300,000 reservists in a dramatic bid to reverse setbacks in his war on Ukraine. The announcement led to an exodus of more than 180,000 people, mostly men who were subject to service, and renewed protests and other acts of defiance against the war.

The fight: Ukraine mounted a successful counteroffensive that forced a major Russian retreat in the northeastern Kharkiv region in early September, as troops fled cities and villages they had occupied since the early days of the war and abandoned large amounts of military equipment.

Photos: Washington Post photographers have been on the ground from the beginning of the war — here’s some of their most powerful work.

How you can help: Here are ways those in the U.S. can support the Ukrainian people as well as what people around the world have been donating.

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