In 2005 Turkish Foreign minister stated “I believe that Turkey will become a full member of the EU in the end. Then those who have some hesitations about Turkey will have totally different views”.
In fact, “Turkey’s orientation towards the institutions of the West dates from the creation of the Turkish Republic in 1923. Since then, commitments to Westernization and modernization have been central themes of Turkey’s state ideology”  .Indeed, Turkish political elite considers that accession to the EU is a “symbol for the successful completion of the long‐term Ataturk revolution” 
On the other hand, from the European perspective and according to the last European progress report; Turkey has significant deficiencies from a political, economic and even institutional perspective. And so, Turkey’s membership might not be very well perceived from the European angle.
In fact, even thought significant political and economic changes were made, Turkish accession to the EU is still at a “slow pace”. Some consider that this is due to the fact that turkey’s membership will push the European borders to “some troubled region”  , and as a consequence the EU will “acquire direct contact with region of instability”  .
And so, if for some, “Turkey will weaken the EU because not only it does not belong to the EU geographically and identically but also because it has many structural and institutional weaknesses”  for others “a literate and qualified Turkish population will make a positive impact on the EU”  .
Therefore, the question here will be whether the Turkish membership will strengthen or weaken the European Union. And my thesis is that Turkey’s membership could affect not only the nature but also the functioning of the EU.
In order to answer this question, focuses will be made on the liberal intergovernmentalism theory. In fact this theory considers that “members will calculate the advantages of enlargement in terms of the cost and benefits of socioeconomics interdependence of various types”  . And so, liberal intergovernmentalism seeks to analyze how can we “rescue and adapt the nation states mainly by analyzing state preferences not only in economical but also in geopolitical and ideological field”  .
Hence to achieve this ‘Chapter I’ will approach how Turkey’s membership will strengthen the European Union ‘Chapter II’ will analyze how Turkey can weaken the EU and finally ‘Chapter III’ will be a synthesis.
“The European Union has never been an exclusive club. From the beginning of the integration process, fellow European countries were welcome to apply for membership. However, as the Union was deepening its integration and growing in size, the question of where and when to stop the enlargement became controversial”  .
In fact, with Turkey’s possibility to join the EU many debates seems to be emerging. Therefore, it seems necessary to the EU to “a democratic governance system to ensure that a Union of 28 or 30 or more countries can function effectively – not become a recipe for stagnation or even implosion.
For the accession to be possible Turkey has also to maintain its progress in both economic and political because “regression would be fatal to its goal of EU membership”  .
2.1- Turkey Weakening the EU:
Many European leaders have argued that the European identity will be lost if Turkey joined the European Union. For instance, former German Chancellor Helmut Kohl once said that a Muslim country like Turkey does not belong in Europe. In addition, the former President of France, Valéry Giscard d’Estaing stated in an interview in Le Monde in 2002 that “a future inclusion of Turkey in the Union would be the end of Europe since Turkey is not a European country.” 
In fact, from the union’s perspective the accession of a country is “rational” if it provides security to the union and raises the economical benefit. However since Turkey has a small economy and has limited trade volume, many assume that it will have “marginal effect on growth in the current EU”  . As the numbers that were published concerning this subject shows Turkey is considered to have the poorest income in the region. And so, “Turkish accession (…) would increase regional economic disparities in the enlarged EU by an estimated 9%, representing a major challenge for cohesion policy”  .
In addition to that, Turkey’s demography is also considered as a burden to the EU. In fact, Turkey’s population estimated at 73 million is considered one of the largest populations in Europe. And so, with the accession of Turkey there is a risk that migration from Turkey to other European countries raises. Moreover, Turkey’s demography might also affect negatively the decision making in the European Union. As Laffan and Stubb note “there are fears that Turkey as one of the largest states in the EU could deteriorate not only the voting relations between the members states but also the whole political and institutional European architecture”  .
And so, with a population predicted to increase to 83 million by 2014, Turkey will be “the most powerful country in the voting system”  . In fact, if Turkey joined the EU, Turkey will have right to 96 members in the European parliament and by this she will be joining the “club of the big countries” such as France, Germany, Italy and the United Kingdom. So with this sharing system Turkey will have a proportion of 12, 8% of votes. This is why smaller countries such as Holland are opposed to this enlargement. Actually, they refuse the idea that Turkey, a new coming country will play such an important role in the decision making of the union whereas their role is being reduced with every enlargement. In fact, with Turkey’s adhesion, and a European union with 28 countries, Germany, France, the United Kingdom and Turkey will be deciding the future of the 24 others.
Turkish demography is also considered a problem because the Turkish population in mainly Muslim. In fact, some government insisted to mention the “Christian nature of the EU” in the draft of the European constitution in 2003 and this shows to what extent some might refuse the idea that countries without “Christian tradition” become members of the EU.
Moreover, “recent polls show that the majority of Europeans now oppose further enlargement of the European Union, and that Turkey receives particularly low levels of support in France, and across Europe more broadly, mainly because it is perceived as religiously different”  .
Furthermore, “Turkish accession means that the EU in reality swaps the instability problems of a stable neighbor with severe instability problems of Iran Iraq and Syria”. In fact, “Turkey’s difficulties in gaining EU membership might be better understood as practical geopolitical problems associated with enlargement”  . And so, being caught between the Middle East and the Caucasus “would make the enlarged EU more exposed and vulnerable”  .
Finally, Turkey’s relation with its neighboring European countries does not bring any help and so “Turkey faces two local rivals (Greece and Cyprus) in the EU who hold veto power over Turkish accession”  .
2.2- Turkey Strengthening the EU:
In opposition, Turkey might positively influence the European Union.
First of all, and from an economical perspective, Turkey is considered as one of the largest market in the world. “It is the seventh major import partner with the EU and the fifth major export partner”  . As Avery notes “its growing economy and young labor force would bring benefits for the single market”  . And so, since EU will need in the future young and cheap labor, Turkey’s accession might then be helpful for the future development and the economic growth of the European Union.
Besides, Turkey is a large country with a large demography, and so its potential as a market of good is important. In fact, as the statistics shows turkey is the seventh major important partner of the EU and the fifth major import partner.
In addition, and since the construction of the oil pipeline Baku-Tbilisi-Ceyhan Turkey’s role as “a key transit country for energy supplies”  is also imperative to the EU.
And so, “It can be argued that in economic terms Turkey not only is important to the EU both for its impact on internal and external economic relations but also that it will strengthen the EU’s economic capabilities”  .
Secondly, “Admission of Turkey to the European Union would provide undeniable proof that Europe is not a closed “Christian Club” ”  . In fact, with Turkey’s accession the union will appear as a more tolerant society. And so, with this integration “Europe could play an inestimable role in future relations between the “West” and the Islamic world. This can also help promoting the “soft power” of the European Union and reinforcing it.
Moreover, due to her geo- strategic position “Turkey would add new dimensions to the Union’s foreign policy efforts in such vitally important regions as the Middle East, the Mediterranean, Central Asia and South Caucasus”  .And so; this will help the union gain an important role in those regions. For instance, concerning the Middle East region, Turkey’s membership would be very helpful to the EU. In fact, the good relations that Turkey entertains with both Israeli and Palestinians will help increasing the union’s weight and this “could be put to good use in common efforts towards peacemaking and stabilization in this strategically critical region”  .
Furthermore, concerning the European Security and defense policy “Turkey’s considerable military capabilities and the country’s potential as a forward base would be important and much-needed assets. In fact, Turkey has participated in the work of the convention to the future of Europe and brought her own vision to improve the European security and defense policy so that she can be able to face today’s challenges.
In addition, “As one of the strongest NATO partners, with a clear orientation toward ESDP, Turkey would be of great value for the European defense system”  .
Finally, refusing the integration of Turkey, might affect the credibility of the EU. In fact, as Smith notes “The sense of responsibility toward the candidate countries, the sense of shared European identity, the strategic imperatives favouring big bang enlargement and the fact that the EU could not have backed down from its promises without a serious loss of credibility and legitimacy all helped to sustain the momentum”  .
“Turkey has two souls: one secular and European, the other Asian and Muslim”  . And this is where the whole problem stands.
On one hand, Turkey tend to join the EU and resemble to the European countries and on the other questions about whether Turkey is European or whether Turkey should join the EU are still subject of debates.
In fact, another problem needs to be raised here: The Turkish public opinion. Actually, “The Turkish public is becoming increasingly resentful towards the EU because of a perception that, while the country is negotiating membership, the EU itself is still debating whether or not it should be allowed in”  .
Even thought Turkey has made many reforms in order to attain the European “standard”, some changes still needs to be done.
First of all and from a political perspective, Turkey has ratified two UN treaties the first concerning civil and political rights and the second social and economic rights but this is still not sufficient. The European Commission still argues that “political, civil, economic, social and cultural rights are not fully guaranteed and that more efforts are needed to enhance the coherence of legal provisions and practice”  .
From an economic point of view “Turkey’s recent economic reforms have shown it capable of lowering inflation and promoting enterprise growth while weathering two recent, regional economic shocks”  .
And so, if liberal intergovernamentalists, such as Moravcsik, perceives “economic groups as the key driving force for integration” then with the changes that were made Turkey can be perceived as capable of being member of the EU since both Turkey and the EU will benefit from this integration. In fact and as we said before, Turkey is an important market of good for the EU and can provide the young labor force that the union needs which makes it eligible to be a member.
From a religious point of view, it’s true that Turkey is a big country with a population mainly Muslim, but let’s not forget that “12 million Muslims live already in Europe and many more are likely to make their way to Europe”  . In addition, Albania and Bosnia-Herzegovina are also Muslim countries and potential candidate to the EU and no one is objecting their potential candidature.
Finally, “a “NO” to Turkey—now or in the very near future—would have extremely grave and negative consequences not only for the nearby region but also for European security interests”  .
And so, the thesis that Turkey’s membership could affect not only the nature but also the functioning of the EU is proven. In fact, even if the arguments that proves that Turkey will strengthen the EU seems to be more convincing from my perspective, the idea that Turkey will bring changes to the nature of the EU seems to be a fact whatever one’s conviction is. However, the changes can be seen differently according to one’s perspective. And so, being convinced that Turkey will weaken the EU, then the changes will be seen negatively and vice versa.
“In his recent book, The Limits of Europe, EU Commissioner Frits Bolkestein warns against European overstretch. Turkish accession, he argues, would reduce Europe to a glorified customs union, and create risks for the European project.
What Bolkestein meant, as he made clear in September 2004, was that Turkey’s large population might well create a more Muslim Europe, either by intra-European migration or by EU voting mechanisms weighted by population size (…)The advantages for an enlarged Europe, he argues, lie in exporting stability but at the risk of importing instability”  .
However, And based on the arguments showed below, we can say that the conditions that are presented as “weakening the EU” are not very convincing anymore. In fact, since the enlargement in 2004, things have changed. And so, if the European Union would like to prove today, that she’s a united international actor, and if the European Union would like to prove that having one purpose might bring together actors no matter how different they are, but willing to work for that purpose, then the EU should accept Turkish membership.
But what about the alternative presented by the French president Nicolas Sarkozy? Will turkey become a privileged partner instead of a full member? And what about the possibility to make some changes for reducing Turkey’s influence before Turkey’s entry to the EU, as it was the case with the Nice Treaty before the eastern enlargement?