Not so:
Conversion requires both circumcision and mikva for the male: The Conservative Jewish process of conversion requires candidates, .....to appear before a beit din, or rabbinic court, to explain... to commit themselves to live as Jews, observe the Commandments, and raise any children with whom they may be blessed in the Jewish community and faith. Male candidates are required to undergo circumcision or, if already circumcised, to have a symbolic ceremony. All converts complete the rituals of conversion by immersing themselves in a mikvah."
I found this item through a skeptical mind and google. Thanks for the good advice.
As in primitive Christianity, immersion marked a significant turning, a physical affirmation of an inner choice and commitment. Ritual purification was also used by those involved in the Temple worship.
Rabbi Myron Geller's article at www.interfaithfamily.com/article/issue21/mgeller.html