President Vladimir V. Putin escalated a tense showdown with the West on Thursday, saying that Russia had launched a new intermediate-range ballistic missile at Ukraine in response to Ukraine’s recent use of American and British weapons to strike deeper into Russia. In what appeared to be an ominous threat against Ukraine’s western allies, Mr. Putin also asserted that Russia had the right to strike the military facilities of countries “that allow their weapons to be used against our facilities.”His warning came hours after Russia’s military fired a nuclear-capable ballistic missile at Ukraine that Western officials and analysts said was meant to instill fear in Kyiv and the West. Though the missile carried only conventional warheads, using it signaled that Russia could strike with nuclear weapons if it chooses.
