The U.S. military has launched an expanded, more sophisticated training program of Ukrainian forces that is focused on large-scale combat and meant to bolster Ukraine’s ability to take back territory from Russian forces, the Pentagon’s top general said Sunday. Gen. Mark A. Milley, chairman of the Joint Chiefs of Staff, said on a flight from Washington to Europe that the training began Sunday at the Grafenwoehr Training Area in Germany and will continue for five or six weeks. About 500 soldiers will go through the initial version of training, focused on what the military calls combined-arms warfare, in which tanks,...