Actually that would not have been the case formerly, back when the 747 was developed, for example. And it should not be the case today, but for the almost totally-subsidized AirBus "Competition", and the extortionate practices of countries playing off their "business" against Boeing and Airbus...demanding co-production contractions as part and parcel of their order...but for that, Boeing could charge as needed and tell the market countries that want co-production deals to "take a hike."
The downsizing of U.S. commercial production capacity has seriously hurt the ability of the U.S. to turn around and produce for war. I don't believe it prudent to rely for such production on nations that regard us as "the Main Enemy." I'm sure you know who I mean.
Um... Taiwan? Italy? Japan? Which of these regards us as "the Main Enemy?"