I doubt whether the doctor was ordered to "attend" any sort of "war". He was probably posted to some medical unit in Iraq to help the sick and injured - mainly Bitish servicemen but his professional ethics would have obliged him to tend Iraqis as well. He was not ordered to commit any warlike acts, legal or illegal. He refused a perfectly legal order to go somewhere to perform his normal duties, and should suffer the consequences. In Iraq, I believe his status would have been "on active service", which in my day would have rendered his offence more serious and increased the penalties.