William J. Burns, the director of the Central Intelligence Agency, cautioned that he had seen no “practical evidence” that would suggest such a move was imminent.
The director of the C.I.A. said on Thursday that Russian President Vladimir V. Putin’s “potential desperation” to extract the semblance of a victory in Ukraine could tempt him to order the use of a tactical or low-yield nuclear weapon, publicly discussing for the first time a concern that has coursed through the White House during seven weeks of conflict. The director, William J. Burns, who served as American ambassador to Russia and is the member of the administration who has dealt most often with Mr. Putin, said the potential detonation of such a weapon — even as a warning shot — was a possibility that the United States remained “very concerned” about. But he quickly cautioned that so far, despite Mr. Putin’s frequent invocation of nuclear threats, he had seen no “practical evidence” of the kinds of military deployments or movement of weapons that would suggest such a move was imminent. “Given the potential desperation of President Putin and the Russian leadership, given the setbacks that they’ve faced so far, militarily, none of us can take lightly the threat posed by a potential resort to tactical nuclear weapons or low-yield nuclear weapons,” Mr. Burns said during a question-and-answer session following a speech he delivered at the Georgia Institute of Technology. He spoke in response to a question from former Senator Sam Nunn, of Georgia, who helped create the program that brought nuclear weapons out of Ukraine and other former Soviet states 30 years ago. Tactical weapons are sometimes called “battlefield nukes,” smaller weapons that can be shot out of a mortar or even exploded like a mine, as opposed to “strategic” weapons that are put on intercontinental ballistic missiles. Russia has a large arsenal of tactical weapons; the United States keeps comparatively few. Low-yield nuclear weapons have been designed to produce a fairly small explosion, which sometimes blurs the difference between conventional and nuclear weapons. Mr. Burns also argued that the disclosure of Mr. Putin’s intentions by U.S. intelligence officials before the outbreak of the war had made it harder for Mr.
