歐洲人從中世紀對地域、封建領主以及基督教教會的認同轉化為對民族的集體認同，並以此作為基礎建立和鞏固民族國家，進而完成了歐洲中世紀邁向近代發展過程中的社會整合。歐盟自1990 年代以來建構集體認同的目的就是要在歐洲共同的文明、經濟與政治發展的基礎上，培養公民對歐盟的認同感以使歐盟發展成為「合眾國」，但隨著歐盟東擴的進程，會員國數目的不斷增加，再加上伊斯蘭文明的加入使得歐盟的文明背景複雜化，利益訴求亦趨於多元化，故有衝擊既存整合目標之可能性。本文從歷史層面來分析歐洲人之文化認同差異；從社會與政治層面探討會員國權益與歐盟公民之偏好；最後再從外在威脅與壓力對於歐盟「共同外交與安全政策」之決策機制與在國際社會之角色等之影響，來探究歐盟東擴對代表歐盟整合深化之單一的歐盟集體認同之塑造與發展是助力或是阻力。

The evolution of European Identity was from local, regional and Christian
identity in the middle age to national identity in modern age. The aim of
European Union at taking shape of collective identity for Europe since
1990’s, which is based on cultural, economic and political development, is to build up the European Identity for citizen, this in turn, is positive for the establishment of “United States of Europe.” But Eastern enlargements complicate the Christian civilization via the accession of new member countries with muslin and orthodox civilization. The interest of member countries and preferences of European people are although to be multi-faceted.The original goal of European integration, namely building-up of “United States of Europe,” could be reversible. In this article the consequence of the Eastern enlargement of European Union for taking shape of European identity will be in three parts examined. The first part reviews the differences of cultural identity among new and old member countries, the second part analyzes social and political dimension of the interest of EU-members and preferences of European Citizen, last but not least the decision making mechanism and the function of the “Common Foreign and Security Policies”will be dealing with in the third part.