Dmitry Medvedev, the deputy chairman of Russia’s Security Council, on Feb. 18 threatened to use nuclear weapons against the U.S., the U.K., Germany, and Ukraine if Moscow loses all occupied Ukrainian territories. Medvedev, who is also a former president of Russia, has repeatedly threatened to use nuclear weapons but the threats have so far failed to materialize. His critics say that his statements are bluff rather than Russia’s genuine plans and are intended to scare the West into making concessions. Medvedev had previously portrayed himself as a liberal but has become one of Russia’s most agg…