Ukrainian President Volodymyr Zelenskyy vowed Monday not to retreat from Bakhmut as Russian forces encroached on the devastated eastern city they have sought to capture for six months at the cost of thousands of lives. Less than a week ago, an adviser to Zelenskyy said the defenders might give up on Bakhmut and fall back to nearby positions. But Zelenskyy on Monday chaired a meeting in which top military brass “spoke in favor of continuing the defense operation and further strengthening our positions in Bakhmut.” Later in his nightly video address, the president reported that his advisers unanimously agreed to...