novel - Story about boy living in a city sheltered from post-nuclear fallout?

I remember reading a story (I think it was a single book, though it may have been a series) when I was younger that took place after a nuclear holocaust (it probably wasn't described as such, but that's the distinct impression I get looking back on it). Humanity had retreated into a walled "safe zone" several generations ago to protect themselves, and everybody knew that it was still deadly outside at the time the book was set. Early in the book, our protagonist met a girl named either Aubrey or Audrey, who turned out to have bionic eyes. At some point, he found an arcade game simulating a fighter jet, which he instinctively knew how to fly. It turns out that this was because

of a mystical connection to his hitherto-unknown twin brother, who had received extensive training (in preparation for war?).

It also turns out that the game was actually a recruitment tool (à la The Last Starfighter). The last detail I remember was when he and Au(b/d)rey went outside the safe zone (I think in a real plane?) and found

that it was perfectly hospitable outside; the entire war was a ruse perpetrated by the extraordinarily rich to force everyone else into hiding, so they could all have huge estates without running out of land.

I know these are all fairly obscure details, but I'm hoping that that's offset by their specificity, and that they're enough for someone who has read the story to recognize it.