The threat of Russia potentially using tactical or low-yield nuclear weapons in Ukraine cannot be taken lightly, but the CIA has not seen a lot of practical evidence reinforcing that concern, CIA Director William Burns said on Thursday. Burns’ most extensive public comments since Russia invaded Ukraine on Feb. 24 underscored concerns that the biggest attack against a European state since 1945 risks escalating to the use of nuclear weapons. Earlier on Thursday, Dmitry Medvedev, deputy chairman of Russia’s Security Council and a close ally of Russian President Vladimir Putin, warned NATO that Moscow would deploy nuclear weapons and hypersonic missiles in Kaliningrad, a Russian enclave in the heart of Europe, if Sweden and Finland joined the Atlantic […]