There are a number of threads here which will tell you that you can wear most any tartan you like. But I certainly feel that being a veteran of the US Army is more than pleanty of justification for wearing the tartan.

I have a SportKilt "works" in US Navy tartan, because I'm a former sailor, myself. I rather like it, though it has to be admitted that it is in no way traditional, and I find myself thinking that, somewhere not too far down the road, I'll also get a wool one in the tartan, pleated to something other than "random."