The maritime border dispute between Croatia and Slovenia takes root from Slovenia’s desire to reach international waters without passing through the territorial waters of Croatia and Italy, and Croatia’s regulations in its domestic law contrary to this desire. Both states claim sovereignty over the Piran Bay, a very small piece of land that cannot be seen on many maps, so the maritime border cannot be settled by compromise. This situation causes big problems, especially for fishermen of the two neighbor countries. The main documents related to this issue are as follows: 

1. Memorandum of Understanding (1954) : According to this Memorandum signed by Italy, Yugoslavia, the US, and the UK, the administration of a part of the Free Territory of Trieste, including Trieste, Zone A, was given to Italy, and a part of it, including the Piran Bay, Zone B, to Yugoslavia.[2]
2. Osimo Agreement (1975): The Free Territory of Trieste was divided definitely by this agreement signed by Italy and Yugoslavia and came into effect in 1977. According to this agreement, Trieste remained part of Italy, but Yugoslavia had the right of free entry to the Port of Trieste. By this agreement, the territorial and maritime borders between two states were determined.
3. The Opinions of Badinter Commission[3]: The Badinter Commission, established by the European Economic Community on August 1991 to deal with the dissolution of Yugoslavia, handed down 15 decisions. The third among them concerned the border dispute between Croatia and Slovenia. According to this opinion, the borders of the republics who declared independence would change only by compromise between parties. Otherwise, the pre-existing administrative borders would continue to be valid.
4. Racan-Drnovsek Agreement/Treaty on the Common State Border (2001): According to this agreement signed by the Prime Ministers of Croatia and Slovenia, 80% of Piran Bay would be given to Slovenia so it could reach international waters. In return, the four villages which caused the territorial border dispute would be under the rule of Croatia. Moreover, it was envisaged that a joint police patrol would be established, and a law would be enacted to prevent the possible problems among fishermen. However, this agreement met very strong response in Croatia and was not approved by the Croatian Parliament. Thus, it never came into effect. 

The declaration of Croatia’s Exclusive Economic Zone (EEZ) in 2003[4] added a new phase to the existent territorial waters issue. Slovenia and Italy protested this declaration by arguing that Croatia has not a right to make such a decision unilaterally because this decision will affect the territorial waters of Slovenia and Italy. Croatia applied for EU membership on February 2003 and was warned also by the EU not to announce its EEZ. Despite the intense international pressure, Croatia did not declare this Zone because of very strong support from its population. Thus, by changing the name from ‘Exclusive Economic Zone’ to ‘Ecological and Fisheries Protection Zone’ Croatia aimed to prevent responses from Slovenia, Italy, and the EU, and to exercise at least some of the rights determined in the UN Convention on the Law of the Sea (UNCLOS) under the title of Exclusive Economic Zone (Chapter V, articles 55-75). Then, in 2006, it was decided that implementations regarding the Zone would become effective on January 1, 2008. But these implementations continued only 75 days. Croatia explained on 15 March 2008 that the EU member states (Slovenia and Italy) will be exempt from these applications. However, this step was not enough to bring the border dispute to a close. On the contrary, the border issue becomes a matter of concern more and more. Both sides continue to defend its own claims and to accuse the other side. 

Then what are these claims? While Croatia wants to determine the border based on the median line or equidistance principle, Slovenia rejects this by saying that this method cannot be applied in all cases.[5] Slovenia argues that Piran Bay has always been a place over which Slovenes are predominant. Croatia rejects this argument and says that there is never ownership of one republic over the Bay and thus, the border must be determined as such it passes through the middle of the Bay. Whereas Croatia refers to the Article 2 and the first paragraph of Article 15 of the UNCLOS to prove the compatibility of the Zone with international law, Slovenia refers to Article 70 and the second paragraph of Article 15 of the Convention.[6] Croatia grounds its arguments on the notion of ‘median line’. Against this, Slovenia puts up the argument that it has historical rights over Piran Bay, and also that it is a geographically disadvantaged country -- Article 70 of the UNCLOS -- and it is essential to find a solution about delimitation of the EEZ according to the equity principle – Article 74 of the UNCLOS. Moreover, Slovenia wants Croatia to respect its ‘right’ to reach international waters. As for the other side, Croatia does not accept that this is a right; it deems this as a ‘need’ for Slovenia, and Croatia has no obligation to meet this need. The other argument of Slovenia is that it is one of the successor states of Yugoslavia so it inherits the right to reach international waters and the undivided coasts of Federation. But this argument is invalidated by the general opinion that the republics whose territorial borders were not determined before the dissolution of Yugoslavia cannot claim a right on maritime borders only on the basis of being a successor of Yugoslavia. In fact, there is ‘the land dominates the sea’ principle in the essence of decisions made by the International Court of Justice in similar cases[7]. Additionally, the international community does not deem Croatia’s declaration of an Exclusive Economic Zone as contrary to international law or Slovenia’s sovereignty rights. Croatia, also, does not accept that this declaration is a unilateral act; rather it is declared according to the rights explained in the UNCLOS. Except these reasons mentioned above, the issue has another dimension for Slovenia. There is an intense Slovene population around Piran Bay, and their main means of living are fisheries and tourism[8]. At the same time, if Slovenia reaches international waters it will be very good for the country’s ship industry. That is to say, the issue is very significant for Slovenia from a financial point of view[9]. Slovenia claims that Croatia will be a loser neither geopolitically nor financially if it accepts Slovenia’s suggestions. However, Croatia acts by the opinion that Piran Bay, where Croatians live also, cannot be left to Slovenia completely.  

Croatia’s application for EU membership in 2003 and opening accession talks in 2005 make border problems more complicated because Slovenia noted that it may hold a referendum for Croatia’s membership if a solution advantageous to itself is not found.[10] In the Progress Report 2008, a road map is suggested for Croatia to complete the negotiation period by the end of 2009. Croatia, who hopes to sign its membership agreement in 2010, worries because of Slovenia’s veto. Croatia was expecting to open 10 new negotiation chapters and to close 5 chapters in Accession Conference on December 2008. But only 1 chapter was opened and 3 were closed because of Slovene vetoes. Slovenia is criticized by the EU for these vetoes. On 19 December 2008, France’s European Affairs Minister Bruno Le Maire warned Slovenia not to use the border dispute issue as an excuse to block Croatia’s accession period[11]. Similarly, Olli Rehn, European Commissioner for Enlargement, called for Slovenia and Croatia to solve this problem among themselves without making it a part of accession talks. The new EU President Czech Republic also noted that this dispute must be solved bilaterally. Still, Slovenia has the upper hand. Whereas the EEZ was mentioned under the title ‘Fisheries’ not under ‘Priorities’ or ‘Regional Issues and International Obligations’ in the 2005 Accession Partnership Document[12], in 2007 it was counted among ‘Priorities’ and ‘Political Criteria’[13]. This development made the EU dimension of the dispute definite. This is a chance for Slovenia to solve the border problem through the EU accession talks, not through the international arbitration suggested by Croatia. Slovenia says that the reason for its vetoes is some maps and documents presented to the EU by Croatia which include incorrect information about controversial issue, i.e. territorial and maritime borders. Slovenia thinks that Croatia tries to solve the problem as a fait accompli. Croatia rejects this accusation, and blames Slovenia for trying to block Croatia’s negotiations and misusing its veto power to arrive at the conclusion it wants.  

When we come to suggested solutions, none of them looks very promising. There are three ways offered by Croatia. First, Slovenia will accept the border passing through the middle of Piran Bay and Croatia will provide a sailing line for Slovenia to reach international waters. Second, Croatia will continue to implement its EEZ but Slovenia and Italy will be exempted. And third, border dispute will be solved by international arbitration. Slovenia does not accept these ways except for the last one. There is no definite statement on Slovenia’s rejection of international arbitration. However, Slovenia wants a solution within the framework of 2001 Racan-Drnovsek Agreement which is certainly refused by Croatia[14]. There is one more suggestion supported by both Italy and Slovenia: to form a single joint zone in the Adriatic. Actually Italy wants to maintain the status quo for maritime borders, preferring to return to the situation before Croatia’s declaration of an EEZ. This is obviously not accepted by Croatia.  

Piran Bay continues to be one of the urgent issues to be solved for two neighbor countries. Nevertheless, compromise becomes more difficult day by day because it is not a geographic problem anymore; it turns into a political issue completely. Unfortunately this situation causes hostile feelings between two nations which slam the door on a compromised solution. It sounds like this ‘bloodless war’[15] will be at the top of the agenda frequently in 2009 on account of Croatia’s EU accession talks.

References 

1.     Slovenia’s Position on the Border Issue between Slovenia and Croatia

      http://www.mzz.gov.si/nc/en/tools/news/cns/news/article/141/8471/

2.   Ten Points of the Slovenian Foreign Ministry with Regard to Croatia’s Negative Statements on Slovenia

      http://www.mzz.gov.si/nc/en/tools/news/cns/news/article/141/22958/

3.   The Conundrum of the Piran Bay: Slovenia v. Croatia-The Case of Maritime Delimitation

      http://papers.ssrn.com/sol3/papers.cfm?abstract_id=990183

4.   Press Conference by Dr Rupel on Slovene-Croatian Relations

      http://www.mzz.gov.si/nc/en/tools/news/cns/news/article/141/9656/?type=98

5.   The UN Convention on the Law of the Sea, the European Union and the Rule of Law

What is Going on in the Adriatic Sea?

http://www.fni.no/doc&pdf/FNI-R1208.pdf