Ukrainian President Volodymyr Zelensky has called on his soldiers to hold out in the Russian region of Kursk. Contrary to reports that Russian troops are pushing the Ukrainians back there, Zelensky said the bridgehead was strong. “We are holding our ground and I thank every soldier for their bravery,” he said in his nightly video address. “We must not forget that the Kursk operation serves a strategic purpose. The war must return to the area from which it started. This is the case when a buffer zone is created on the territory of the aggressor.” With the surprising advance at the beginning of …