I live in Argentina with my Israeli husband and our 8 year old son. After a crisis in our marriage whereas my husband has left the house, we have decided that our child would stay with both of us alternatively in a sort of joint custody. A few days ago, my husband told me that he has moved with our child to Israel. Is he allowed to do so?

No! according to section 5 of The Hague Convention on the Civil Aspects of International Child Abduction, your husband does not have the right to decide on his own where your child would live. Our practice has represented a similar case in the past, and learned that the law in Argentina accords parental rights to you as a parent, and that hence there needs to be an agreement by both you and the father, to take your minor child out of the Argentinian border/jurisdiction.