Even more importantly, many people are worried that Europe, even as it opens up internally, may close itself off from the outside world, forming a sort of "Fortress Europe."
更重要的是，由於歐洲共同體之間流動性增高，許多人擔心歐洲會對內更開放、對外愈封閉，而形成所謂「歐洲堡壘」。