Scholars and jurists have long debated the interaction between national and international legal systems: some endorse a monist view that international law is directly incorporated into a state's domestic legal order, and others take a dualist approach, arguing that the two legal systems are separate and distinct. (1) The European Union (EU), which was created by treaty but operates in many ways as a single entity, (2) has struggled to find its place between these two poles. In the 2008 decision Kadi v. Council, (3) the European Court of Justice (ECJ) embraced the view that the EU and international law systems were distinct. (4) Recently, in Hungary v. Slova k Republic, (5) the ECJ held that the Slovak Republic's decision to ban the President of Hungary from entering its territory did not violate EU law. (6) In so doing, it directly incorporated international law in a way that indicated that international and European law were intertwined and thus suggested limitations on the bright dualist line espoused in Kadi. While Hungary might be distinguished away as an aberrant case in the movement to ward dualism, its reasoning could signal a broader monist role for international law in the EU.
Hungarian President Laszlo Solyom was scheduled to travel on August 21, 2009, to the Slovakian town of Komarno, where he was to help inaugurate a statue of Saint Stephen, founder and first king of the Hungarian State. (7) The timing of the trip was notable for both countries. In Hungary, August 20 is a national holiday celebrating Saint Stephen, while in Slovakia, August 21 is considered a "sensitive date" because on August 21, 1968, Czechoslovakia was invaded by five Warsaw Pact countries, including Hungary. (8) The planned visit led to diplomatic tensions between the two countries. (9) After diplomatic discussions, (10) the Slovakian government formally refused the Hungarian President entry into its country, citing the public security exception to Directive 2004/38, (11) an EU law granting EU citizens the right to move and reside freely within the EU's member states. (12) President Solyom complied. (13)
The visit's cancellation did not end the dispute. In a note issued on August 24, 2009, Hungary argued that the public security exception to EU Directive 2004/38 did not form a "valid legal basis" to ban the President from entry. (14) Unsurprisingly, the Slovak Republic disagreed. (15) At that point, Hungary brought the matter to the attention of the European Commission and requested its opinion on whether there had been a violation of EU law. (16) The Commission announced in an informal letter issued on December 11, 2009, that it could find no violation, as EU law does not apply to official visits by foreign heads of state. (17) Not satisfied with this response, Hungary formally brought the question to the Commission on March 30, 2010. (18) After briefing, the Commission issued a reasoned opinion, finding that the treaty does not apply to heads of state and thus that there was no breach of EU law. (19)
Still unsatisfied, Hungary filed an action against Slovakia in the European Court of Justice, only the sixth time in the court's history that one member state had brought a direct action against an other. (20) Hungary argued that the Slovak Republic had violated the terms of Directive 2004/38 by prohibiting President Solyom from entering its territory. (21) Next, it stated that the EU's freedom of movement laws were not subject to the rules of international law, contending "that if the European Parliament and the Council of the European Union had wished to make the exercise of freedom of movement subject to rules of international law," they would have done so explicitly, but they had not. (22) Hungary further argued that the Slovak Republic had not met Directive 2004/38's narrow exception criteria. (23) The Slovak Republic, supported by the Commission, argued that President Solyom was not visiting as a private citizen but as a head of state, and that the EU does not cover the regulation of diplomatic relations between states. …