KYIV, Ukraine — Mykhail Podolyak barely flinched as air raid sirens wailed in Kyiv, signaling incoming Russian missiles. Sitting in his office at the heavily fortified presidential administration building in Ukraine’s capital, the adviser to the head of the office of Ukrainian President Volodymyr Zelensky said the sirens have become a normal part of life six months into the war with Russia. “We’re getting used to this new lifestyle — we are used to the wailing sirens now and to the bombardments, because the Russian Federation is mostly aiming at the civilian population and civilian infrastructure,” he said in an...