Putin issues warning to Europe about Ukraine gas debt

Putin’s letter to 18 leaders, released yesterday by the Kremlin, is part of Russia’s efforts to retain control over its struggling neighbour, which is teetering on the verge of financial ruin and is facing a pro-Russian separatist mutiny in the east.
A large Russian military build-up alongside the Ukrainian border has also raised fears that the Kremlin could use the tensions in eastern Ukraine as a pretext to invade, following Moscow’s annexation of Crimea last month.