Contempt of Court
Both contested and uncontested divorces always result in an official agreement or judgment, signed by the court and binding on both parties, spelling out the rules regarding every relevant aspect of life after the divorce, including Child Custody and Visitation, Child Support, Spousal Support or Alimony, Property Division etc.
If one spouse fails to abide by the decree the other spouse may petition the Court for him or her to be held in contempt. The court can then impose fines and other sanctions, including attorneys fees until the other party complies with the divorce orders.