In my comment threads there has recently arisen references to Stanley Kurtz's writings on the state of marriage in Scandinavia and The Netherlands. I encourage anyone encountering these ideas for the first time to read firsthand what Kurtz has actually said and what others have said in return.
As for what Kurtz himself has written, a few comments can be found on MarriageDebate.com or National Review Online's The Corner, but the bulk of what he has said can be found in two articles in The Weekly Standard together with respective follow up replies to his critics on National Review Online. The first article was titled "The End of Marriage in Scandinavia" (02/02/2004) with a follow up response to Andrew Sullivan, "Slipping Toward Scandinavia." The second article was titled "Going Dutch?" (5/31/2004) with a follow up response to M.V. Lee Badgett, "Unhealthy Half Truths."
I have responded to Kurtz's claims on a number of occasions on this blog collected into this category. Another great collection of responses was due to a number of authors at Amptoons collected under this heading. From the above two collections of posts you can find more responses for and against, but please don't miss this paper (pdf) by Professor Badgett.
Kurtz's biggest fear is that same-sex marriage is part of a movement that will lead to the equalization of marriage and cohabitation. Jonathan Rauch, though, has a brilliant piece in the latest issue of The New Republic [subscription required, but it's worth at least getting the trial subscription] as to how permitting same-sex marriage will strengthen the message that marriage is important, whereas prohibiting it will lead to a vast array of alternatives to marriage including a push for the legal and social equivalence of cohabitation to marriage. Rauch's article becomes particularly relevant after rereading Kurtz.