Re: When do you know? C-Note: Per, You're not alone in your situation. You and your wife sound like you have worked hard to succeed professonally. College prepared you to do just that.
I am in a similar situation with my wife. If she's had a crappy day at work our kids and myself bare the brunt of her unhappiness. I'm not certain if this is good advice but I have personally stop placing blame for "this and that" and avoid the "who's right and wrong". I reminded my wife that I was not one of her employee's and that I was her husband. Maybe stress management is all that is needed for both of you. I have tried opening positive dialog between us to discuss her day, feelings, wants and needs. Since fidelity is not an issue, and the fact that she still comes home when not away on business, I also would recomend that you seek marraige counsuling.
I don't even know how to go about bringing up the idea of getting marraige counsuling with my wife. That may start an argument by itself. But if there is still love between you two the topic should be discussed and action taken.
Good Luck