I am an atheist (not Jewish) and my soon-to-be wife is Jewish (Ashkenazi of Polish ascent). She doesn't practice, and she says she is not a believer. We are French and live in Paris. This may or may not be useful information, but at least, it will explain why my English might not be very colloquial.
We plan to have a single baby (for several reasons). If we have a boy, she wants for him to be circumcised when he is 8 days old. As a humanist, I strongly believe that any irreversible body alteration done without medical necessity and without consent is just wrong. I oppose the circumcision at this age and asks that he is allowed to decide for himself when he can consent.
I might give in, and let it happen, but only if not doing it would cause very serious bad consequences for my son. I have researched the Internet (both English- and French-language), and my understanding so far is that postponing the circumcision, while understandably shocking to my wife, would not have dire consequences for my son. That he would still be Jewish. That he would still be welcome in the community, at least later in his life, when he decides to get circumcised by himself. So my question is: is my understanding correct?