Is it hard to admit you have PTSD or do you even know you have it?

My husband is a civilian contractor in Kuwait/Iraq and he has been there for over 3 years straight with a few two week R&R's. He is showing signs of PTSD. I have read a wonderful book Down Range, talked to a chaplain and my therapist and they all agree something isn't right. He wants a divorce and I don't think he knows what he wants or is in the right place of mind. How do I tell him I think he needs to talk to someone? I know a lot of guys that have PTSD and refuse help or don't think they have it.