To some parents, Japan's official entry Tuesday into the Hague convention on cross-border child abductions doesn't represent the light at the end of the tunnel, but the arrival of more obstacles in the prolonged effort to retrieve their children, experts say.

The Hague Convention on the Civil Aspects of International Child Abduction was drafted in 1980 to ensure that children abducted and taken overseas by a parent involved in a failed international marriage will be promptly returned to their country of habitual residence.

Japan's refusal to sign the convention earned it a reputation as a "safe haven" for international child abductions. But from now on, the Foreign Ministry will be legally bound to locate abducted kids and facilitate their return at the request of parents abroad. The same will apply to children whisked away from Japan, as long as the country where the child is staying is a signatory of the convention.