This framing gets the supply chain backwards. Cymer makes the source vessel, the part that generates tin droplets and converts them to plasma. But the laser that actually powers that process is a 17-ton, 40kW CO2 beast with 457,000 parts, built exclusively by TRUMPF in Germany. And the optics, mirrors smooth to tens of picometers that literally no one else on Earth can make, come from Carl Zeiss, also German, organized as a foundation that no foreign government can force into a sale. ASML only manufactures about 15% of an EUV machine's components. The rest comes from roughly 1200 suppliers concentrated in Germany and the Netherlands. Seizing Cymer gets you one subsystem with no laser to drive it and no optics to focus it.
The real problem with this theory is that EUV isn't a product with a capturable bottleneck. It's more like a standing wave of institutional knowledge distributed across organizations that have been co-developing at picometer tolerances for 30 years. TRUMPF's leadership described the arrangement as a "virtually merged company" with open books across all three firms. That kind of integration knowledge doesn't transfer via acquisition. China has been throwing enormous resources at this with access to published research and former ASML engineers, and their prototype still isn’t expected to produce working chips until 2028-2030. Saying the US could grab Cymer and start producing EUV machines is like seizing a transmission plant and calling yourself a car manufacturer.