It pre-supposes that what was best for the USA and world was Intel being maximally successful, rather than there being a market for x86 chips. That's not clear

It pre-supposes that what was best for the USA and world was Intel being maximally successful, rather than there being a market for x86 chips. That's not clear at all. If American capitalism is defined by anything it's competition, something Intel has sometimes unfortunately tried to squash. The real answer here is not to come up with artificial Intel-specific legal kludges like forcing them to cross-license to AMD, but rather to adjust copyright and patent law to define APIs and ISAs as non-protectable.