Sonny is a second generation Italian, so he feels some patriotism toward the only country he's ever lived in but at the same time, he is his father's son.
Exactly right. He was his father's son when he says "
They're saps because they risk their lives for strangers."
And Michael even tells him "
Now that's Pop talking."
And what does Sonny respond to him? "
You're god damn right that's Pop talking."
Which makes me think of the deleted scene at the Hospital in Part 1, before they go in to see Genco. Vito looks at Michael's medals and asks him what they are. And when Michael explains to him what they mean, Vito says (paraphrasing here) "You perform these miracles for strangers?"
Sonny's sentiments about the war and such were a result of growing up around his father.
