Direct Applicability of European Union Law

The notion of 'direct effect' is taken from American jurisprudence and that of the International Court of Justice, it means that a rule adopted in different legal system than the states - ie that of international law - not only creates rights and obligations for Member but also for private parties, both in their relations with states and international organizations concerned as well as between them. The principle of international law in the Vienna Convention art. 26 - "pacta sunt servanda" - Every treaty in force is binding upon the parties and must be performed by them in good faith, oblige states to respect the treaties they have signed. However, international law does not regulate the conditions in which legal norms contained in treaties be integrated into the international justice of the States concerned to be applied but it is left to each state that regulates them.