In certain cases, a chargé d'affaires may be appointed for long periods, such as when a mission is headed by a non-resident ambassador who is accredited to multiple countries. In addition, a mission may be downgraded from an ambassadorial to a chargé d'affaires level to show displeasure, yet avoid taking the extremely serious step of breaking diplomatic relations. For example, Saudi Arabia and Thailand have not exchanged ambassadors since 1989, due to the still-unresolved Blue Diamond Affair.[6]