The next enlargement of the EU with new Member States have an enormous impact on these countries as well as on the EU. The basic conditions for Applicant States in effect means two things: being a functioning constitutional state with a competitive market economy. These first two criteria are not negotiable. Enlargement have an impact on the security sector of Applicant States and relations between European security organizations. The new realities and changing character of the NATO and OSCE will redefine the relations between European security organizations and EU Security and Defense policy (ESDP) will look different after the enlargement.