While Russian troops are capturing territory, a Pentagon official said that their “plodding and incremental” pace was wearing them down, and that the military’s overall fighting strength had been diminished by about 20 percent. And since the war started, Russia has lost 1,000 tanks, a senior Pentagon official said last week…

Soon after his appointment, General Dvornikov tried to get disjointed air and land units to coordinate their attacks, American officials said. But he has not been seen in the past two weeks, leading some officials to speculate as to whether he remains in charge of the war effort.

Russian pilots also continue to demonstrate the same risk-averse behavior they did in the early weeks of the war: darting across the border to launch strikes and then quickly returning to Russian territory, instead of staying in Ukrainian air space to deny access to their foes. The result is that Russia still has not established any kind of air superiority, officials said.