[susan53]

I've written materials for high level military English for a while now, for a combined forces group involved in buying technological equipment. It's mainly involved researching new developments in weaponry, surveillance and defence equipment, finding materials from the net (it's scary what's out there) and using them to develop the course. You don't have to be an expert because as soon as you raise the topic the students take over and tell you more than you ever wanted to know. (You would not believe some of the things currently under experimentation - and I bet those are only the ones they're allowed to talk about.) In fact searching the net turned up some stuff one of the students had written himself, and I was able to use that for one of the lessons. But you need to find material initially which you can use to form the basis of the language and skills syllabus and to develop activities around.
You can also find materials for Military English here while MacMillan publish a course called Campaign which has a related website that includes links to other military English sites.