Is refusal to circumcise excommunicatable in Judaism?

Answer 1

I assume that this is referring to a parent who refuses to have his child circumcised as opposed to a child refusing to be circumcised (at only eight-days old, he would have to be a very intelligent child) or a Mohel (professional circumciser) refusing to perform a circumcision either due to scheduling complications or medical complications that may result from "abnormal conditions below the belt."

No. This parent will not merit kherem. Kherem is very serious and only given out sparingly to those who willfully violate the law and attempt to make others violate the law as well, usually with the guise of authority. If this were the case that refusal to circumcise would merit kherem, certainly open homosexuality, clear Sabbath violations and infringements of other commandments would lead to some many excommunications that you would have no community to excommunicate from. This parent, is, however, denying their son the ability to eat of the Pascal Sacrifice since no uncircumcised person may eat of it. He is also denying his son the spiritual connection to the Jewish people and to Abraham, his progenitor, by failing to do this.

Of course, if there is a serious medical condition that would make circumcision life-threatening or cause serious complications for the son, the requirement to keep the child alive and in good health supersedes the requirement to be circumcised.