Ukraine’s daring ground offensive has taken the fight to Russia, but not nearly as much as its leaders would like because, they say, the United States won’t let them. The U.S. restricts the use of long-range ballistic missiles it provides to Ukraine, which wants to aim them at military targets inside Russia. Ukraine’s offensive, along with a barrage of drones and missiles that Moscow launched this week, has intensified pressure on the Biden administration to ease its cautious approach to the use of Western weapons in escalating Ukrainian attacks. The Biden administration says its careful deliberations, including which advanced weapons...