> Tell that to the many nations that are not part of EU.
Here are the nations that are not in the EU currently. Many of them are currently in the process of becoming EU members.
Russia (Are never going to apply for EU membership under current status.)
Belarus (Are never going to apply for EU membership under current status.)
Switzerland (EFTA. Submitted EU application in the year 1992. Has been frozen since that time.)
Iceland (EU candidate) (EFTA/EEA)
Macedonia (EU candidate country)
Montenegro (EU candidate country)
Serbia (Not yet EU candidate but has applied for membership)
Bosnia and Herzegovina (Has not yet applied for EU membership but is expected to do so in the future)
Kosovo (Has not yet applied for EU membership, when it might submit an application is unclear at this point in time)
Moldova (Are going to submit application in the future. When is unclear. No time plans on application as is.)
Ukraine (At this point in time it is too early to know when an application might be submitted. No time plan have been put forward for this move as is.)
Turkey (EU candidate and have been since 1985.)
Georgia (Have shown interest for EU membership, but not put out plans for EU application.)
Armenia (? I am also not sure if they meet EU legal requirement for EU membership or application as is.)
Azerbaijan (? I am also not sure if they meet EU legal requirement for EU membership or application as is.)
Micro states in Europe have not yet applied to EU and remain outside EFTA/EEA. They are however many in close cooperation with EU and many of them use the Euro as currency and have other deals that give them access to the internal market on the same level as EU member but without representatives and voting rights.