The commander overseeing the nation’s nuclear arsenal said Tuesday that any cuts to modernization efforts would force a reconsideration of America’s nuclear strategy just as adversaries China and Russia are advancing differing nuclear threats to America.

“Let me be very clear: You cannot life-extend Minuteman III,” said Adm. Charles Richard, the head of U.S. Strategic Command, describing the 50-year-old intercontinental ballistic missiles that form the land-based leg of America’s nuclear triad.