A couple of thoughts.
It's impossible to have 're-experiencing' symptoms in relation to an event that you never actually 'experienced' (that actually occurred) in real life in the first place. The more the anxiety/distress is about something that 'could have happened' (but didn't), it doesn't make any sense to me to consider this a 'traumatic event/ trauma' in one's past fueling current distress.
There's obviously a continuum and room for nuance (and debate) here. If a veteran served in Iraq in 2008 and was doing daily patrols in an area where there were constant enemy attacks (IED's, snipers, firefights, etc.) but that veteran was just 'lucky' enough never to have actually been shot at, blown up, or injured, I still would say that the veteran was clearly 'exposed to a warzone' sufficient for it to meet Criterion A for development of possible PTSD. However, other situations (to me) clearly don't meet criterion A. Some examples:
1) being stateside (never deployed) during the Vietnam era but being afraid that one would be deployed is not a 'Criterion A'
2) being in the Navy and serving on an aircraft carrier during normal operations in the Mediterranean sea and, at certain points, having to don/doff nuclear/biological/radiological protective gear (as part of routine, universally-experienced, precautionary training/ preparation drills) is not a 'Criterion A' event
There are others, but you get my point. There will ALWAYS be a requirement of clinical judgment (and careful interviewing) around the putative or potentially traumatic event (PTE) and if/how/why the individual experienced it as 'traumatic.' There is a subjective component to this and there always will be. They eliminated Criterion A2 from the DSM-5 (after DSM-IV) because they were largely considering events (originally) that anyone would find traumatic (i.e., canonical traumas like getting shot, getting raped, or seeing someone turn to mist in front of your eyes). However, in cases that are at the borders or fringes of Criterion A, to me, it is absolutely essential for the clinician to interview the patient around the question of what, specifically, did you experience as 'traumatic' about that experience?
Another concern is quite practical. Our trauma-focused therapies (PE/CPT/EMDR) generally require focus on a 'most traumatic event' as part of how they are implemented. If someone is deployed to a large base in Saudi Arabia for three years (but no discrete traumatic event happened to them) but they are claiming that 'the entire deployment' was their 'trauma' because they were in constant fear of something happening (that didn't) how do you handle that as 'the event?' It's too diffuse and if someone is having crippling anxiety, nightmares, hyperarousal, etc. about an event that 'didn't happen' vs. did happen 10 years ago then you're probably less likely dealing with PTSD and more likely dealing with other diagnostic entities or clinical case formulations.
