It’s a new era of nuclear risk. Here’s how US should respond

The world is sliding into a new age of nuclear risk — in which miscalculation or accident could lead to catastrophe. The great progress the nuclear powers made in the 1990s through arms control and nonproliferation, reducing nuclear weapons and securing loose materials, is being undone.

The latest retreat came in Minsk, Belarus, on May 25, when Russian Defense Minister Sergei Shoigu and Belarusian Defense Minister Viktor Khrenin signed a formal agreement paving the way for Russia to deploy tactical nuclear weapons in Belarus. These are short-range nuclear weapons such as artillery shells, bombs and missiles for use in battlefield operations — not the long-range weapons deployed on intercontinental missiles. It is not known when Russia will deploy tactical nuclear weapons in Belarus, but the agreement seems to represent the latest act of saber-rattling by President Vladimir Putin since he invaded Ukraine last year. Mr. Putin had earlier said that Belarus would have nuclear facilities ready by July 1 and that Russia would remain in control of them. The United States maintains about 100 tactical nuclear weapons at six bases across five NATO countries.

Thirty years ago, Belarus acceded to the Non-Proliferation Treaty and declared its intent to become a nonnuclear state. By May, 1993, it had transferred to Russia the tactical nuclear weapons inherited from the Soviet Union. It sent 81 SS-25 nuclear-armed missiles back to Russia by 1996. The new deployments upend that history. If Russia stations tactical nuclear weapons on Belarusian soil, it could bring Belarus into a nuclear conflict, both as a launchpad and a possible retaliatory target. Moreover, the deployment appears to be another step in establishing Russia’s control over Belarus, with the connivance of its despot Alexander Lukashenko, who has attempted to extinguish the democracy movement there.

Nuclear dangers are growing in other places, too. AntiPutin militias conducted an armed raid near the Russian town of Belgorod near the border with Ukraine. Much about the attack is unclear. But Belgorod is known to be the location of a central storage facility for some of Russia’s approximately 2,000 tactical nuclear weapons. Western observers do not know to what extent they were exposed to fighting nearby, but the episode is worrisome.

Elsewhere in Ukraine on May 22, the Zaporizhzhia Nuclear Power Plant, Europe’s largest atomic power station, suffered its seventh power loss since Russia’s invasion, leading the head of the International Atomic Energy Agency to warn the plant is “extremely vulnerable.” The plant’s six reactors are shut down but depend on continuous power supply for cooling. Energoatom, Ukraine’s state nuclear company, blamed Russian shelling for the latest outage, which promoted a warning the plant is “on the verge of a nuclear and radiation accident.”

On top of all this, the nuclear arms control treaties that did so much to reduce the danger at the end of the Cold War are now disintegrating. The Intermediate-Range Nuclear Forces Treaty of 1987, the first to liquidate an entire class of nuclear-armed missiles, ended in 2019 with U.S. withdrawal under President Donald Trump over alleged Russian violations.

On Feb. 21, Mr. Putin announced that Russia was suspending its participation in the New START accord limiting strategic nuclear weapons, the last remaining major nuclear-arms control agreement between the United States and Russia in force. Meanwhile, China is rapidly building up its nuclear arsenal, seeking to reach the strategic levels held by Russia and the United States, refusing to enter negotiations and creating an even more complex three-way arms race.

Nuclear dangers have seemed remote since the Cold War ended. But with international tensions rising along with nuclear arsenals, the corresponding risk that mistakes or misunderstandings lead to disaster are increasing. The United States needs to continue trying to minimize the likelihood of such outcomes. The West should plan now for a renewed negotiation push with Russia, if possible, after the Ukraine war and to find ways to entice China to the table. And it is essential that everyone, including Russia and the United States, avoid complacency and carelessness.