Russia pummeled Ukraine’s capital with hundreds of drones and missiles early Thursday, the latest in a string of deadly Russian strikes this week. The attacks suggested that President Vladimir V. Putin had little intention of de-escalating his war, after he declared recently that he believed it was “coming to a close.” Explosions shook Kyiv, the capital, over several hours Thursday morning as Ukrainian forces tried to intercept and shoot down the drones and missiles, some of which evaded overwhelmed air-defense systems. The attack included cruise and ballistic missiles that Moscow often stockpiles for mass bombardments. As the sun rose, rescue...