Ukraine threatened to blockade the Russian Black Sea Fleet yesterday in an act of solidarity with Georgia that risked escalating the conflict. After flying to Tbilisi to assure Georgians of his country’s support, President Yushchenko signed an order imposing tough restrictions on the Russian fleet, which is based in the Ukrainian port of Sevastopol. Mr Yushchenko’s decree instructs Russia to give 72 hours’ notice of any movement of ships, aircraft or personnel in Ukraine. The Ukrainian authorities were given the power to alter those plans. The Ukrainian Foreign Ministry had already warned Russia that it will bar ships from returning...