The two mutually exclusive visions or ‘Weltanschauungen’ are known as the Westphalian System of International Relations and the European Model of Transnational Governance. While the origins of the former go back to the Peace of Westphalia (1648) and the start of the Early Modern Period, the second has emerged only after the 1992 Treaty of Maastricht. The hallmarks of the Westphalian System are absolute sovereignty and national citizenship & national democracy, whereas the European Model is characterised by shared sovereignty and dual citizenship & dual democracy.
The European model is a deviation from the Westphalian system. The decision of six European states in 1951 to share sovereignty in the field of coal and steel in the ECSC was described at the time as ‘a revolutionary breakthrough in the classical pattern of international relations’. In their dealings with other states, however, the founding members of the present European Union continued to act in line with the rulebook of the Westphalian system. In fact, the organisation of the United Nations and the Council of Europe are both ‘Westphalian’ institutions. Member States deal with each other on the basis of sovereignty and equality. They respect each other’s territorial integrity and have to refrain from interference in the internal affairs of other states. In the time of Von Clausewitz that was notably regarded as a casus belli.
The overriding argument for the six founder states of the EU to deviate from the prevailing paradigm in international relations stemmed from their determination not to inflict war on each other again. Nie wieder Krieg! As the sharing of sovereignty in a limited field proved to be a reasonable price for the guarantee of peace, they broadened their special cooperation to the whole of the economy in the EEC. In its landmark decision in the case Van Gend en Loos, the EC Court of Justice established that, by sharing the exercise of sovereignty in a number of fields, the member states had created an ‘autonomous legal order’ among themselves. A year later the EC Court confirmed its approach and explicated in the case Costa v E.N.E.L. that, within this autonomous legal order, European law takes precedence over national regulations. Uniformity of interpretation of European (EC/EU) law is guaranteed by the Court itself, notably via preliminary rulings.
The theory of democratic integration
The decision of the European Council in 1973 to describe the then Communities as a ‘Union of democratic States’, may be regarded as a conceptual turning point for the new polity. The theory of democratic integration, which the present author has recently published, suggests that, if two or more democratic states agree to share the exercise of sovereignty in a number of fields with the view to attain common goals, the organisation they establish for this purpose should be democratic too.
Seen through this lens, the subsequent decision to initiate direct elections for the European Parliament in 1979 forms the first step in the democratisation of the EC/EU. It was followed by the agreement contained in the 1987 Single Act to introduce qualified majority voting in a number of fields. Evidently, national vetoes and parliamentary control are incompatible in an international organisation. The EU crossed the conceptual Rubicon by introducing a citizenship of the Union in 1992. As a Union of states and citizens the EU evolved beyond the Westphalian paradigm. Although many commentators failed to grasp the consequences of this unprecedented step, the theory of democratic integration regards the introduction of citizenship as an indispensable precondition for the creation of a democracy at the level of the Union. In simple terms, no democracy without citizenship. From this perspective, the decision to include democracy in the core values of the EU, taken in 1997 at the summit of Amsterdam, was a logical step forward. The new citizens were to have their own ‘Magna Charta’ in the form of the Charter of Fundamental Rights of the EU proclaimed in 2000.
The novelty of the Lisbon Treaty is that it construes the EU as democracy without turning the Union into a state. This unique construction induced Habermas to formulate his enigma: How should one imagine a for closer cooperation necessary, supranational organisaton, which complies with stringent demands of democratic legitimacy without assuming the shape of a State? 
In its decisions of 19 December 2019 the EUCoJ solved the longstanding riddle by establishing that the EU has not only an autonomous legal order, but also an autonomous democracy. These verdicts imply that the EU may now be described - from the perspective of the theory of democratic integration - as a Union of democratic states and citizens, which also forms a constitutional democracy of its own.
Notwithstanding the emergence of the European Model of Transnational Governance the BundesVerfassungsGericht has endeavoured to evaluate the EU from within the Westphalian paradigm. The result of this effort consists of a series of three verdicts, which demonstrate a perplexing logic and cohesion. In the Maastricht-Urteil of 1993 the BVerfG describes the EU as a ‘Staatenverbund’, thereby implying that it is impossible for the EU to have citizens. In the Lissabon-Urteil of 2009 the BVerfG describes the European Parliament as a supplementary institution, thereby implying that it is impossible for the EU to have a real parliament. By establishing in the EZB-Urteil of May 2020 that the EUCoJ has gone ultra vires, the BVerfG puts beyond doubt that - in its view - it is impossible for the EU to have an independent Court too.
Debating the conflict
Hardly ever in the history of legal theory has the power of paradigm presented itself so forcefully as in the case of the BVerfG versus the EUCoJ. Although both Courts found their judgments on the same treaties and provisions, their findings are worlds apart. The BVerfG and the EUCoJ do not merely disagree, but they hold each other’s position for untenable. Obviously, no polity - neither state nor society - can function in this manner. The only way to resolve a dispute between two highest courts of law is through academic debate. It may therefore be suggested that both the upcoming German Presidency of the European Council and the Conference about the Future of Europe offer excellent opportunities for holding a –coronaproof- academic conference about the question ‘whether the EU can be explained in terms of the Westphalian system of International Relations and, if so, how?’
 Kapteyn and VerLoren van Themaat, The Law of the European Union and the European Communities, Alphen aan den Rijn 2008
 C. von Clausewitz, Vom Kriege, www.clausewitz.com
 EC-Bulletin, 12-1973
 J. Hoeksma, From Common Market to Common Democracy, Oisterwijk 2016
 Die Furche, May 2012
 Cases Puppinck ECLI:EU:CL2019:1113 and Junqueras Vies ECLI:EU:C:2019:1115
 Cf J. Hoeksma, European Democracy, Tilburg 2019