The state has a centralized form in ten of the fifteen member states, and is constitutionally decentralized in the remaining five. However, no clear correlation exists between degree of constitutional decentralization and particular federal or regional arrangements. The intensity of some local autonomies in a number of the centralized states further blurs the dichotomy. A more pronounced difference appears between states in which the territorial division of power (federal or regional) was accomplished within a nationally homogenous society, and states in which homogeneity does not feature.[23] In the former group, one can still perceive a tendency toward the rationalization of federalism that Mirkine-Guetzevitch identified in Austria and Germany - the two new federal states in the "New Europe" of his era. In Spain and Belgium, the rationalization tendency is considerably less evident. Mirkine's thesis holds that "as long as federalism is based on politics (nationalism, dynastic traditions, etc.), it escapes rationalization. Politics is substituted by law only from the moment federalism appears as a purely legal solution and the constitution ceases to be a tool for protection of political or national interests and becomes instead an objective element in the legal defense of interests, both at the local level and at the center.."[24] While this conclusion is certainly true, it is also, unfortunately, tautological.[25]
[23] Italy's centrifugal tendencies offer evidence to support the thesis that national diversity is not the only cause of political tensions.
[24] Op. cit., p. 26. The emphasis is in the original. A few lines above this passage, Mirkine-Guetzevitch characterized rationalized federalism, which we would today call `cooperative federalism', as a system in which "...instead of difficulties, obstacles, or reciprocal conflicts between local and central authorities, [there exists] a logical and harmonious system of considerable autonomy and prudent decentralization."
[25] For further analysis of the return of the dualist conception of "devolutionary" systems, such as Belgium, Canada and Spain, see K Lenaerts, "Constitutionalism and the many faces of federalism" American Journal of Contemporary Law, vol 38 (1990), particularly pp. 237-253.