In December 2004, the European Union EU will decide whether or not toopen accession negotiations with Turkey. Of the countries involved in the 2004enlargement of the EU, Turkey remains the only contested applicant that has not yetbeen able to acquire a date for the start of the accession negotiations. This isdespite Turkey having first applied to join the then EEC about 45 years ago. In thisrespect, the Turkish case is deemed to be extremely important in assessing theenlargement rationale of the EU. This article analyses the justification of EUenlargement in general and with respect to Turkey and tries to judge whetherTurkey is an asset or a liability regarding the enlargement policies of the EU. Thestudy concludes that the justification for including Turkey in this enlargementprocess has not followed a consistent pattern during these four decades and that theasset/liability assessment can only be understood by taking into account a numberof other factors in addition to the fulfilment of the Copenhagen criteria