Seven weeks after sending a new commander to Ukraine to oversee a refocused invasion, Russia faces a truth that a former American defense secretary, Donald Rumsfeld, defined as the necessity of going to war with the army you have, not the one you might wish to have. The Russian military, beaten down and demoralized after three months of war, is making the same mistakes in its campaign to capture a swath of eastern Ukraine that forced it to abandon its push to take the entire country, senior American officials say. 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 […]