Ukraine is bracing for a grisly Russian offensive in the Donbas. Moscow has concentrated hundreds of thousands of troops in the country’s east, using brute-force tactics and human waves in a bid to chip away at the Ukrainian Armed Forces’ defenses. Amid a recent surge in fighting, many military analysts believe the long-awaited Russian offensive is already underway and is expected to accelerate as the first anniversary of the invasion approaches. “Something is brewing in the east,” said Jonatan Vseviov, secretary-general of the Estonian Ministry of Foreign Affairs. “More and more Russian soldiers are arriving on the front,” he said....