While President Joe Biden has kept public statements strategically ambiguous about the consequences of Russian use of nuclear weapons, the administration has been sending private messages to Russian leadership for several months.
Those messages have warned of the grave consequences of the use of tactical, battlefield nukes and smaller precision nuclear weapons Russia would deploy to escalate to de-escalate the war effort in Ukraine, sources told The Washington Post.
Keeping U.S. retaliatory actions vague is intended to be a nuclear deterrence to Russia amid its invasion of Ukraine that began Feb. 24.
There are not specific details of whether those private messages were sent after Russian President Vladimir Putin suggested everything is on the table – and is not "bluffing" – as he attempts to regain lost ground in eastern Ukraine. Biden this Sunday issued a public warning against nuclear weapons use, telling "60 Minutes" only: "Don't. Don't. Don't."
"If he was really thinking very seriously about using nuclear weapons very imminently, he almost certainly would want us to know that," Carnegie Endowment for International Peace's James Action told the Post. "He would much rather threaten nuclear use and have us make concessions than actually have to go down the path of nuclear use."
The State Department has been sending the warning messages, but sources would not say what is in them.
Russia is planning to annex four areas of eastern Ukraine after holding referendum votes. If those areas were "accepted into Russia, according to Russia's Dmitry Medvedev, Russia will use "any Russian weapon, including strategic nuclear ones" and potentially hypersonic weapons.
"Russia has chosen its path," Medvedev said. "There is no way back."
The Biden administration notes the latest Russian statements are not the first time they have threatened the use of nuclear weapons in order to achieve its "special military operation" goals in Ukraine.
"What everyone needs to recognize is that this is one of, if not the most, severe episodes in which nuclear weapons might be used in decades," Arms Control Association Executive Director Daryl Kimball told the Post. "The consequences of even a so-called 'limited nuclear war' would be absolutely catastrophic."
Ukrainian military intelligence chief Vadym Skibitskyi said in a televised interview Russia will not hesitate to use tactical nuclear weapons "to stop our offensive activity and to destroy our state."
"This is a threat for other countries," he said. "The blast of a tactical nuclear weapon will have an impact not only in Ukraine but the Black Sea region."