He can SENSE he's an American! He doesn't know it, he doesn't feel it, he senses it! Guess another of his random superpowers kicks in and now he has the psychic ability to determine nationalities! Hahaha!
He forgets everything about who he is or how to use his powers, but he can look at some fatigues and immediately identify them as being from World War II! Hahaha!
And his code versus killing is so utterly ingrained in him that he follows it when he doesn't even know who he is! Even when he's in the middle of a war! Even though I'm guessing this isn't all that distant one direction or the other from the point where he'd wind up executing a bunch of alt-universe Kryptonians! Hahaha!
And this is the style of comics that editorial wants to bring back! Hahah-