A new push by the Kremlin frames the war as a counterterrorism operation and seeks to rally Russians to support the fight, officials and researchers say.
President Biden’s remarks reflect the urgent concern in Washington and among Western allies that Russia may be searching for a pretext to unleash a battlefield nuclear weapon.
Top officials from the United States, Britain and France cautioned that there was no change in Russia’s nuclear posture and that they believed no decision had been made to use a tactical nuclear weapon.