I've recently run across this article as I was doing some personal research looking into causes and associated causes of auto-immune disorders and PTSD in those who served in Combat Zones but who may not have been in direct combat or frequent shooting situations (Support personnel or those who spent lots of time in "rear areas" but were exposed to frequent mortar and rocket attacks, perimeter guard duties, travel to fire bases, etc). In laymen's terms, this article suggests that constant stress caused by the apparent life threatening events in the combat zone, unrelieved by being able to "return fire" or some other satisfying physical and / or psychological response causes the body to produce chemicals which (by remaining un-neutralized by the satisfying response) can cause physical damage to the central nervous system and the body's immune system. The most apparent damage being physical pain and inflammation associated with auto-immune disorders like Rheumatoid Arthritis, nerve damage, or physical changes in the brain and brain chemistry.

A local Psychologist confirms the stress of the "Rules of Engagement" (no engagement of enemy or returning fire unless ordered to do so) and the Standard Operating Procedures requiring all weapons to be turned in and secured while in base camps, most likely contributed to the production of "fight or flight" chemicals in the body. We went about our daily activities in rear areas with the constant threat of sapper attacks, rocket and mortar fire, sniper fire or a random round, with no weapon to protect ourselves or our buddies close at hand.... this was a big stressor for most of us!