Use this military condolence letter as a jumping-off point for when a veteran has died.
I'm so sorry to hear about your loss. {Name} was a brave {man/woman}, both as a soldier and after the war. {He/she} was a confident, self-possessed person with a strong moral compass. It is difficult to even begin to describe how much {he/she} will be missed.
More than just as a friend, I want to say how grateful I am as a citizen to have had {Name} protecting and fighting for my country. {He/she} was a treasure and will surely be missed.