They don't produce them within the US. They're building some factories to do so in the future, but as of now their output is 0.
However, the US government has / can have control over Micron's production. They are headquartered in the US. They have the intellectual property and know-how to erect a vertically integrated supply chain. Europe doesn't have this strategic investment.
Micron/Crucial has bailed the consumer market. Enterprise only now, FWIW.