The control mechanism established by the European Convention on Human Rights plays a key role in the preservation of democracy and the rule of law at European level. In this context, the European Court assumed the role to ensure an effective protection of the fundamental rights and freedoms, according to the principle of the "practical effect". The Convention is a living instrument which must be interpreted in the light of the changes occurring in society, especially as it was intended to guarantee "not rights that are theoretical and illusory but rights that are practical and effective". The Court holds that "regard has to be held to the fair balance that has to be struck between the competing interests of the individual and of the community as a whole". In both cases, the state enjoys a certain margin of appreciation in determining the provisions to be adopted in order to ensure the conformity with the European Convention. In this way, one may hope to see the perpetuation of the general spirit of a Convention protecting not only the human rights but also "the ideals and values of a democratic society".