(Reuters) – Russia launched its long-awaited all-out assault on east Ukraine, unleashing thousands of troops in what Ukraine described as the Battle of the Donbas, a campaign to seize two provinces and salvage a battlefield victory. FIGHTING * Ukraine’s defence ministry said the aim of Russia’s new offensive in eastern Ukraine was to seize all of the Luhansk and Donetsk regions, establish a land link between those territories and Crimea, and destroy Ukraine’s armed forces. * An aide to President Volodymyr Zelenskiy said Russia’s new offensive in eastern Ukraine will fail because Moscow’s force…