Although diplomacy is very crucial for every government and it is undeniably accepted that diplomatic system of each country seeks development of beneficial and strategic relations, what is much more important is existence of professional and skillful diplomats in diplomatic system of each country. We believe that personal differences of diplomats can make big differences in foreign policy of countries. Those diplomats who have cognitive superiority can accomplish their missions properly. Cognitive control is our ability to compare previous data and situations with current data and situations and make decision in no time and express our decision and ideas in a well-ordered series of properly-chosen words to others. We are absolutely sure this is the most important skill of a diplomat. Furthermore, it should be admitted that a diplomat must be able to speak correctly and have an excellent wording skill.