The slow start to Ukraine’s counteroffensive is by no means an indication it’s failing, the top US military officer said Tuesday, pointing out Kyiv’s forces have a “significant amount of combat power” they haven’t used yet, and their Russian opponents are not in great shape. A month and a half into its counterattack, Ukraine can claim cracking several villages but no major victories. Army Gen. Mark Milley, chairman of the Joint Chiefs of Staff, said it’s too early to make any judgments while Ukraine is still trying to clear mines laid by Russian troops over several months. “Right now they are preserving their combat power,” Milley told reporters.…