Is Divorce Ever Necessary?

I think Anthony Esolen over at Touchstone magazine/ Mere Comments blog is one of the most interesting contemporary writers on moral questions. This summer he wrote about the death of friendship, arguing that the culture's openness about sexuality means there's no longer any space for non-sexual relationships. If two people are close, everyone wonders if they are lovers, with ill effects on friendship and even on simple peace of mind, to his mind.
Here's a post in which he questions the piety --unquestioned even among Christians who understand marriage as a sacrament-- that sometimes divorce is necessary. We've lost the distinction between separation and divorce, he argues. Sometimes separation is necessary. But divorce?
I am wondering about the cumulative effects of divorce upon the culture at large. What does it say for us, that we can stand in front of God and man and vow, till death, to remain faithful to our spouse; and then to break that vow utterly? We would never say, "Sometimes treachery is necessary," or "Sometimes blasphemy is necessary, ," but what else is it when, to secure our own happiness in this life, or so we think, we treat that vow as if it were elastic, or riddled with exceptions, or just an old-fashioned formula? Does it not proclaim from the rooftops, "Duty is a fool's game"?
I especially wonder how Christians can any longer justify it. Where in the New Testament does Jesus say that your duty will bring you unruffled days and exciting nights? We are called to take up the Cross -- and, sad though it may be, for many people that Cross is a spouse. Who is to say that our abandonment of a bad spouse, though perfectly understandable from the world's point of view, is not an abandonment of that soul to perdition -- a soul that we might have been the means of saving, had we remained at our post? The worst marriage I have ever personally witnessed did not end in divorce -- and that simple adherence to duty has been the conduit of grace for at least one soul who, but for a miracle I cannot imagine, would have been lost. That soul, naturally, was the great offender in the marriage.
He also denies that a divorce is "personal."
I also wonder about the divorces (and the adulteries, and the violence) that a culture of divorce causes. For the causal arrow works both ways. When everyone knows he must stay at his post, regardless of fear, then almost everyone will stay. But if desertion is condoned, even smiled at, even celebrated, then the game is up, and every deserter will help to pull two or three along with him. Your divorce helps destroy other people's marriages, too -- consider that, I beg you, my Christian brethren.
Talk about touching a nerve! Read the comments section of his post. Some readers point to vicissitudes of the law that may mean divorce is the only legal way to protect oneself against an alcoholic or abusive spouse. For myself, I think Esolen doesn't fully take into account the fact that in the case of Catholic marriages, you could be divorced legally and still fully married in the eyes of the Church. I think what he means to address is the "try, try again" attitude we all bring to marriage these days, and that is indeed worth re-thinking.