One year ago, Douglass Berg, of Reston, said goodbye to his son and daughter before they boarded a flight with his ex-wife on what was supposed to be a three-week visit to her native Japan. He has not seen the children since.

Stefanie Gardner, a native of Germany, traveled to that country with the two young sons she had been raising in Northern Virginia with her estranged husband, Gregory. Since then, she has refused to allow them to return. He accused her of kidnapping the boys, and a warrant for her arrest was issued in the United States. But a German court has awarded her sole custody.