If you have not willingly given up your parental rights by signing them off or ignoring court documents telling you that she had filed "abandonment" papers, then you are still the legal father. I know there are federal laws to protect military parents from such action while they are assigned out of the country. I can't cite the law, but your JAG certainly can.
Get an appointment with your JAG asap. He can't represent you in a state court, but he will know the regs and he can usually refer you to a competent family law attorney. The JAG office deals with situations like this every day...believe me.
And, Brisgirl825; your comment about his choice of military service is insulting and ignorant. Further, his parental rights can't be terminated without proper procedure and notice. If the procedure has not been done, the new hubby cannot give the child his name. He just needs to get the papers filed (time stops at that point until a decision is made).
So, Armydaddy....get your rear down to the JAG office, get the federal regs that affirm your rights, and get your papers filed to protect them. Again, asap!