Yes! The non-return of a minor under the age of 16 to the country representing the centre of his life, is likely to be regarded as an act of abduction under the 1980 Hague Convention on the Civil Aspects of Child Abduction, which binds both Israel and the United States. The father could initiate child abduction proceedings for the minor's return but the refusal of a 15 year old is likely to be regarded as a legitimate reason for the non-granting of an order for his return to Israel, in a U.S. court, which would hear the Hague proceedings.
The problem may be solved by negotiation between the parents, out of respect for their son's true wishes. If such negotiation succeeds, a new agreement should be drafted which provides for the legal transfer of the minor into the mother's custody and his relocation to the U.S.A and , of course, for the provision of visitation rights for the father. The agreement should be authorized in the relevant courts, in Israel and America. If no settlement is reached, and/or the minor is not voluntarily returned to Israel, then there may be no choice other than to wage a legal battle, in the United States, either for the minor's return, or over his custody.