All I can remember is, the main character is ex-military, got shot up bad in an attack by indigenous/terrorist forces, and was forced to call in artillery on his own position. Survived, got back home, and became a police officer. Seem to remember multiple stories, but might be wrong there
Sounds like Grim Reaper by rlfj
https://storiesonline.net/s/11339/the-grim-reaper-romantic-story
https://storiesonline.net/universe/979/grim-reaper-universe
Yep. Its in the army / Iraq arc of the story. Grim's FOB is about to be overrun, he has the survivors of his squad lock themselves in a bunker while he acts as the artillery observer. Gates are breached and its 'Fire mission upon my position'. A bad case of PTSD results and he leaves the army and returns home where he ends up a cop after much drama.
He didn't leave the Army due to PTSD. He received a medical discharge due to his injuries.
Lonny
Starts out when he is just a little kid. (Like 6?) So it takes a while to get to Iraq. GREAT story.