The good neighbourliness principle in EU law

In summary, this work clarifies the legal framework of the good neighbourliness principle in international law by explaining its legal basis and the rights and obligations of states stemming from it as well as from fields where the principle is applicable. It further examines the functioning of the principle in EU law, focusing on three different legal contexts – on the functioning of the principle in the intra-EU interstate relations, in EU foreign relations and in EU enlargement. Unlike in the first legal context, where good neighbourliness is manifested through the principles of loyal cooperation and solidarity between the EU and its Member States, in the latter two contexts good neighbourliness is applied through conditionality. Having analysed the strengths or weaknesses of the three legal contexts, the work discusses in its conclusion whether the good neighbourliness principle functions better alone or whether it should be applied in EU law through solidarity or conditionality.