By Pavel Polityuk and Michelle Nichols KYIV/NEW YORK (Reuters) – Some draft-age Russians rushed to the borders on Thursday to escape their country’s biggest conscription drive since World War Two, while explosions shook southeastern Ukraine on the eve of referendums planned there by pro-Moscow separatists. President Vladimir Putin’s new mobilisation campaign escalates the seven-month-old war that has killed thousands, displaced millions, pulverised cities, damaged the global economy and revived Cold War confrontation. Though surveys have suggested widespread domestic backing for Russia’s inter…