Rather, it follows the principle of subsidiarity, according to which only those powers and competences are centralised which cannot be exercised more effectively at local level. This principle cannot be applied theoretically. It is experience that permits an assessment of how the national implementation of certain competences may lead to an inefficient outcome.
An awareness of the need to assign powers to a European institution – powers which previously were exercised primarily at national level – can only arise after the failure of the decentralised approach. This kind of choice cannot however be taken for granted because no institution, national or international, readily surrenders its powers to another body.