LOL! I know enough about how US business operates on their own (and it’s likely no different with government contracts) and when a contract is over, they want NOTHING OF IT...just like it never happened.
I strongly suspect Russia looks at their critical defense needs differently (being invaded multiple times has an effect on people) and figures it doesn’t cost that much to buy low-level components (as in chips, for example) for future use, should the need come about. Same for keeping large factories dormant, particularly given their near-infinite land area.