I'm only in it for keeping the muscles working right.
I start 10 minutes in 190 degree sauna to get the old juices flowing and loosen up stiff muscles and tendons.
Then I walk a quarter mile, jog a quarter mile, run a half mile, jog a quarter mile, then walk another quarter mile for a total of a mile and a half.
Then:
3x chest flyes
3x reverse flyes
3x military press
3x lat pulldowns
3x tricep extensions
3x bicep curls
1 set max out crunches for abdomen
I need to add squats and superman/cobra for back and leg work as well. On occasion I'll do leg extensions and calf curls.
After the workout, its 15-20 minutes in the 190 degree sauna.
I only use enough weight for the first set to be fairly easy, 2nd mid-difficulty, and 3rd set enough weight to make me work, but not max anything out.
Three times a week keeps me fit, and I rarely aggravate my old war wounds. 
(Ankle was wrenched backwards so badly that 6 layers of skin died from being stretched across the ankle bone. I drink lots of milk so it didn't break, but I couldn't run again for a year. 3 separate back injuries at work, which is why I do IT now. Upper, middle, AND lower back. Torn rotator cuff in right shoulder. Chronic issue in the wrist from oyster shucking and a motorcycle accident that makes it sound like crackling twigs at times when I pop it to relieve tightness and mild pain) 
It also lets me eat poorly a few meals a week without porking out. Unless you are going for a professional career, not much reason to do the extreme diets or exercise regimens.
First of all, devestated about your war injuries,  sucks bad and I hope people you meet honor the sacrifice you gave!
About your wrist:  welcome to the club,  for me it was a downhill bike accident with 16 : )
Happy to see you working out,  seems to be a good general workout!
if you should ever want a change in your training regime,  you might want to try the bodybuilding cylce kinda work a bunch of track athletes do on their active recovery days.  They foster and maintain general fitness,  arent hard on the body and create a beneficial recovery environment by fostering hgh release etc.
furthermore they only cost you 30 minutes : )
do 1x24  or 2x 12 exercises for 10 reps with a weight you would max out at 12 reps,  and have 30s - 1 min break inbetween exercises.
 I usually picked exercises by machines/ racks standing close to eachother,  which usually results in training muscles in groops.
to visualize,  this is what it could look like:
2x
quads
hamstrings
calv raises
biceps 
triceps
crunches
goodmornings
benchpress
shoulderpress
side raises
pullups
this is very general ofc,  but i guess you get the point.  you can emphasise any muslce groop by doing more exersises for one or the other.
bent over row