學者指出，造成情報失敗的原因除了情報過程的功能不彰以外，決策者亦為其中一項極為重要的關鍵因素。歷史上許多著名的情報失敗案例亦顯示，由於決策者的因素，導致情報運用的失敗，造成政策、軍事行動或危機處理的嚴重失誤。為瞭解造成情報決策失敗的原因與改善之道，本文以情報決策失敗為主題，内容包含探討情報失敗與情報決策失敗的意義概念、情報決策失敗的原因、2003年美國入侵伊拉克行動的情報決策失敗案例、最後提出改善情報決策失敗的方法，期能提供決策參考，避免情報決策失敗，充分發揮情報功能。

Scholars have pointed out the failure of intelligence is not only caused by the dysfunctional intelligence process, but also decisions made by the policymakers. Many historical well-known cases have shown that intelligence collapse depend on the factors of the decision makers, whose unsuccessful poor use of intelligence results in serious mistakes in policy, military operations and crisis management. To understand the causes and improvement of the intelligence defeat, this thesis focuses on the intelligence decision making failure, comprises of the discussion in the breakdown of the construction concept of both intelligence and decision making, the failure causes of intelligence decision making, the deficiency decision case of the Iraq invasion by the United States in 2003, and finally the improvement methods of intelligence decision making. The main goal is to elaborate the complete function of the intelligence system and to avoid further intelligence decision making failure.