These transformations include new technological capabilities such as artificial intelligence, battlefield robots and unmanned aerial systems (UAS) or drones.
"We haven't exactly kept pace with engineering modernization," Rainey said on Monday. "We are witnessing the leading edge of a monstrous disruption of the land domain that is coming."
Manned battlefield vehicles should have robots beside them that can launch UAS, Rainey said.
"We need to get into autonomous heavy lift [and] predicate logistics," he said.
However, Rainey said he agreed with US Army Chief of Staff General Randy George that a separate UAS arm or command should not be set up, at least at the present time.