By that standard, a computer designed and made in USA that would use ARM and C++ would not be American, because at their initial origins ARM was British and C++ Danish (and inspired by the Norwegian SIMULA 67). Even the C programming language cannot be called American by your methodology, because it includes many features taken from the ALGOL 68 language, which were introduced in it mainly by a Dutch team.

The reality is that computer technology is global. It does not belong to any single country.

If you analyze any piece of hardware or software, it aggregates various elements that have their origins in many countries.

What matters is whether you can design and build a complete system, not from where you might have learned each of the great number of things required for this.