I'm digging into my memory, but it seems to me that there were a number of studies that tracked marital disruption among military and non-military. I think those studies or surveys have been done.
On a personal level, I don't know the difference, but I would suspect you would find they're probably reasonably comparable, but maybe not. Certainly the demands of military life, especially tied to deployments and psychological injuries, create huge stress on spouses, and many of those marriages just do not survive. They simply don't survive.
I'm thinking of a friend of mine who suddenly realized that his wife had not been able to sleep for the last five years because he rants and raves, and tosses and turns throughout the night, and she is awake. Suddenly she said that she couldn't live that way, and she left him. That's probably not an uncommon kind of a question.
It would be well worth digging into finding those statistics. The surgeon general would certainly have access to those through the social work system.