There would be an ironic twist if nvidia (who first competed with AMD nee ATI) was forced to license their IP to intel for national security reasons, but it would rhyme with history (x86 licenses to AMD) and benefit the consumer.
Why couldn't Intel fab GPUs for Nvidia? Taiwan just had 2 7+ earthquakes this morning, so we can add that to the geopolitical risk of having a large number of the world's most advanced chip fabs on the island of Taiwan.
Other than process specifics, they could, and that's exactly what happened when the 1980s US Government got worried about a single CPU supplier. The result was (to some extent) modern cheap computing.