Sure why not?
In a global society protectionism isnt really benefiting anybody and the contract was won by an American company AND a European one. Manufacturing takes place in Europe and assembly in the US afaik.
Why does 51 years of being an Airforce contractor make it better than something Northrop and EADS can make? The Airforce did make a good solid investigation on what would be the best deal and the best product that they could get. If the Boeing product wasnt as good as the other option then why should they choose that one?
Nobody wants to have or use an inferior product no matter what it is and especially the military imho.
Choose the best product and the other competitors needs to make their product better to compete.
Price isnt everything.