My teenage daughter wants to join me on a trip to the States to visit my parents who are American, elderly and cannot travel to Israel for medical reasons. Her mother (my 'ex') objects,out of spite.What can be done?

You can file an urgent application ,even jointly with your parents, at the family court,  requesting  it to intervene , and grant permission for your daughter to travel overseas, temporarily, for the purposes of a family visit,and specifally request that she herself be "heard" by a social worker  at the court assistance unit.  Substantial weight is likely to be given to your teenage daughter's wishes if she is found to be sufficiently mature and expresses a clear and genuine wish to view her grandparents. Supporting medical information showing that the grandparents are unable to travel would be required, too. Although your  'ex' will be given an opportunity to respond, unless there are objective and strong reasons for preventing your daughter's travel overseas to see her grandparents, then your  chances of success are high .Your  daughter has a right ,as a minor, under international law to have a relationship with her extended family, and to know her American heritage. If the court finds that the trip is consistent with your daughter's wishes, and her welfare/good, it will override the mother's objections.