Fortitude, by Andy Duncan

The premise of Fortitude is pretty simple--George Patton gets a reboot on his life, and we see him try to change his future.  But the story is of course much more, and is told with a great deal of depth so it's no wonder it was a Nebula nominee in 2000.  The style in which it is told reminds me very much of Connie Willis' time travel to WWII stories and novels (All Clear, for example), except that this one is focused very much on fighting and Willis is mostly about the backstory.  I have a nagging feeling I've read it before, but can find no evidence of it.  So I hung in with it, and can say I enjoyed it enough for 3 stars.