I've always read it as at least a little bit a comment on the Iraq war, but what's it's deal? It's the only anime I can think of that climaxes with a military coup, and its cool that mustang wants to put people on trial for war crimes, but then he gets in power and doesn't do it.
It's also just got a whole plotline about racism, but it feels slightly off? Like minorities are okay if they save your life.
The people of Xerxes were known for blonde hair and golden eyes, Amistrians had blonde hair and blue eyes, although most of them have black hair.