The changing nature of war. One thing that war provides is a live laboratory of what works and does not work on the battlefield:
Ukraine has sidelined U.S.-provided Abrams M1A1 battle tanks for now in its fight against Russia, in part because Russian drone warfare has made it too difficult for them to operate without detection or coming under attack, two U.S. military officials told The Associated Press. The U.S. agreed...
www.yahoo.com
It could be Ukraine and their US military handlers just wanting to preserve scarce resources. Then again drones might be shaping the battlefield in new and different ways that make high tech tanks ineffective.