If Eastern Orthodoxy sees marriage as an eternal and unbreakable bond, why do they permit divorce?

The Wikipedia article for [Marriage in Eastern Orthodoxy](https://en.wikipedia.org/wiki/Marriage_in_the_Eastern_Orthodox_Church) describes in almost poetic terms how marriage cannot be dissolved, even by death, because Christ has defeated death. If I'm interpreting all this correctly, it seems to be saying that marriage is an eternal bond which cannot be broken by anything, similar to how a persons baptism, confirmation, and holy ordination leave indelible marks on the soul of that person, none of which can be revoked. If this is the case, then why is divorce permitted? What is the theology that makes eternal marriage and divorce consistent with each other? Is "divorce" just another way of saying "annulment"? That is, when an Eastern Orthodox says that two people are "divorced", is this just a way of saying that there was never a valid marriage in the first place? (Similar to Catholics)