I've been to Arlington multiple times because my grandfather is buried there. That looks to be a section for career soldiers based on the dates. That isn't the Vietnam Memorial or anything. They bury people in section based on when they die, so while there could be a few who died in Afghanistan or Iraq or something, most of them are going to be career folks who died with 20 years of service.
In response to my own comment. Who thinks, when they sign up for the military (whether it is to get the GI bill or loan forgiveness or whatever) that it is "free." I know I didn't.