A Map of the United States as Seen by Invading Alien

New York and Los Angeles? They have to go. Take out a few monuments in Washington. Flatten Chicago if you have time. Then you're done, as far as our new overlords are concerned.
Alaska and Hawaii? Good news: to the aliens, you don't even exist. You can probably even avoid occupation.
Of course, the rest of us in Flyoverlandia won't necessarily be spared. We nuked Houston ourselves in Independence Day.