Dear Chelsea:

I regret to inform you that I will be unable to join you at your wedding to Marc Mezvinsky on July 31 at Astor Courts in Rhinebeck, N.Y.

The reason is, of course, that you guys didn’t invite me. That’s understandable, since we’ve never met. On the other hand, I do feel somewhat close to you, having watched you grow up in the Clinton White House, during a period in American history I like to call “Before the S—- Hit the Fan.” Also, because you are the child of a Methodist mom and a Southern Baptist dad, and you’re marrying Marc, who was raised in a Conservative — capital C — Jewish home, I, like just about every other Jew, feel obliged to make your special, intimate day my own business.

The amount of commentary on your interfaith wedding is already vast, certain to reach Diana-and-Charles-like proportions by the time your special day comes around. Two weeks ago, it was the subject of an extended feature on the Associated Press, an investigative piece and online forum in the Detroit Free Press (That’s what Detroit has to worry about?), an excellent analysis by David Gibson of Politics Daily and, of course, extensive coverage in the Jewish and Israeli press. The Web site hasn’t had this much traffic since Sandra Bullock decided to get her adopted son a bris.

The comments show a deep concern over the fact that Marc is Jewish and you’re not. Many wonder whether you’ll convert, talking at length about the process, or whether it would even “count.” Others speculate about how you’ll raise your children, whether they will be Jewish, even whether their children will be Jewish. Will a rabbi officiate? Will you wed under a chuppah? Will Marc crush a glass?

“The survival of Judaism as a religion and the Jewish people as a community are eternal worries for Jews around the world,” Gibson summarized, “but rarely do those dual concerns come together as spectacularly as they will in the wedding later this month of former first daughter Chelsea Clinton and the scion of another Democratic clan, Marc Mezvinsky.”

You are probably wondering how people can take something so powerful and intimate as the kind of love that leads to the lifelong commitment of marriage and turn it into a crisis, a cause for hand-wringing and breast-beating, a symptom of the inexorable disappearance of an entire religion and culture off the face of the earth, a kind of genocide-by-“I do.” What deep insecurity must be at work to greet, “We’re getting married!” with “Oy vey!”

Welcome, Chelsea, to the Jews.

But before you peer over your laptop at that handsome fiancé of yours and say, “Marc, what’s with you people?” let me say something many of those shriers will not appreciate: Mazel tov.

Really. I’m very happy you’ve found your soul mate, a hard and precious thing to discover in this world. My wife and I celebrated our 19th wedding anniversary this year, and I know with the benefit of hindsight how much joy, how many laughs, how much pleasure and struggle and growth and life is fated in those few powerful moments of the marriage ceremony. You seem like a nice woman: You deserve a shot at all that happiness.

So why would some Jews decide to turn your special day into some kind of cautionary tale about intermarriage? Why use it to drag out those hoary statistics: 55 percent of all Jews intermarry; the world’s Jewish population is declining, from 13.5 million in 1990 to 12.7 million in 2008; the percentage of young Jews who feel attachment to their religion and to Israel is slipping.

It’s not your fault. You’ve walked into a story that’s been going on for 4,000 years, and at this particular juncture you’re the perfect metaphor: How can we retain our precious Marcs in a world of alluring Chelseas? That’s how a lot of Jews see it: When you’re expecting every knock on the door to be a Cossack, you can’t believe it when it turns out to be, say, Publishers Clearing House. But trust me, they’re mistaken.

To the extent that you are marrying into this story, into this Jewish family, we are lucky to have you. Over centuries of persecution, our most imaginative writers — and we’ve spawned a few — couldn’t contrive a story where the princess openly chooses a Jew. As good as we are at business, the arts and science, we still haven’t learned to take good news well.

But beyond what your choice tells us about a positive turn in Jewish history, your marriage is good news because I trust — I hope — that over time, when the hoopla and/or chuppah are behind you, you will find in the tradition of your husband’s family great wisdom and enduring values. You will find connection and meaning, and an approach to God, family and community that is a comfort and a challenge, accessible and profound.

You get all that, and a husband, too, and my advice is not to let the Gevaltocracy make you feel anything less than wonderful — and anything less than welcome.

Again, sorry I can’t be there to celebrate with you. Maybe at the bris?