民用航空器貿易之「AB大戰」，係指歐盟空中巴士公司（Airbus）與美國波音公司（Boeing）為了爭取訂單，聯合其母國政府，對民用航空器採購商之政府施加壓力，因而引發的貿易爭端，這也正是WTO民用航空器貿易協定（Agreement on Trade in Civil Aircraft ）制定之背景。 我國自二○○二年二月一日正式簽署上述協定，自應遵守該協定第4條禁止使用不合理壓力與誘因影響購機決定之規定。不料同年華航中程客機之採購，卻引發歐盟指控有違前述規定。事件最後在華航宣佈同時向波音、空中巴士購機後落幕，但也顯見AB大戰並未因民用航空器貿易協定之出爐而停息。 由於民用航空器產業目前最大者即為歐美之A、B兩大生產廠商，一旦一造在爭取訂單時，採取了違反民用航空器貿易協定第4條之手段，且得以因控方難以舉証其之違反而免於任何後果，則根據賽局理論，另一造必也會採取相仿之謀略。 根據上述的發現，華航未來的購機，難免會再度陷入腹背受脅、受誘的困境，不過由於舉證責任之困難，美、歐應不致對我國訴諸爭端解決，愈發突顯民用航空器貿易協定第4條規範功能之有限。 / Airbus and Boeing have long been in trade conflict, also known as the “AB War”, under which both companies unite their respective governments to exert pressure on the governments of countries which procure civil aircraft, all for the purpose of securing contracts. It is also the background behind the adapt of the Agreement on Trade in Civil Aircraft. Taiwan became official signatory of the Agreement on Trade in Civil Aircraft on Feb.1, 2002. As a signatory, Taiwan should obey the rules of Article 4 which forbids using unreasonable pressure and inducement to affect decisions on aircraft procurement. However, the procurement of aircraft by China Airlines at the same year was accused by the EU of violating the rule discussed above. The dispute ended finally after China Airlines announced that it would procure aircraft from both of these companies. It also reveals that this war has not been finished even with the existence of the agreement. Airbus and Boeing are the biggest manufacturers in world’s civil aircraft industry. If one of them adopts measures violating Article 4 of the agreement, and is relieved from any consequences because the plaintiff cannot prove the disobedience, the rival side would undoubtedly, at the time, according to the game theory, the take the same strategy. According to the discovery above, in the future the China Airlines will unavoidably fall into same dilemma of being threatened and induced by the manufacturers. However, It is believed that U.S and EU would not easily seek settlement of controversies considering the difficulty in producing proof. It also discloses that the function of Article 4 is obviously limited.