At first glance, Yelets in winter looks like something from a Russian fairy tale. From the embankment I spy the golden domes of Orthodox churches and, down below, ice fishermen dotted along the frozen river. But in this town, 350km (217 miles) south of Moscow, the fairy tale feeling is transient. On the riverbank I spot an army recruitment billboard. It promises a one-off sum equivalent to £15,000 ($20k) to anyone who'll sign up to fight in Ukraine. Close by there's a poster of a Russian soldier taking aim with a Kalashnikov. "We're there where we need to be," the...