At The Kenyon Review website, Hilary Plum has been doing some excellent blogging about questions of empire, writing, canonicity, etc. I left a comment on one post that was mostly just me giving a short version of my canonical nationalism schtick, not because I thought the post was bad, but because the article Plum used as a basis for her thoughts annoyed me. (I wish I had made my gratitude for her own thinking clearer, but I was in a hurry, and it's internet, so...)
Most recently, she wrote a post titled "Writing American Empire" that collects a nice range of ideas about U.S. novelists and the lands the U.S. has been occupying, invading, bombing, etc. recently. Trying to summarize the different points of view would likely distort them, so I'll just exhort you to head over to the KR blog to see what it's all about. If you've ever felt either excited or queasy about the phrase "cultural appropriation", this is a discussion you should read.