Check out Brian Turner's reflections on the origins of some of his poems from Here, Bullet, his book of poems about serving in the U.S. Army in Iraq. Many of them are quite moving, and his work hearkens back to the World War I tradition of soldier-poets writing and witnessing on the front lines. Here is his caveat, which, inevitably, is trumped by his own framing of the poems--that brute factuality which Stevens feared, but which we postmodernists love:
I believe in the saying, Poetry finishes in the reader. I can (and will) tell you about some of the things I wrote in-country, there in the sand, or what was going on in my head at the time (I use my journals from back then to help refresh my memory). But in the end, I truly believe you’ll take it with a grain of salt and decide for yourself what the poem itself is all about.