The development of a joined-up approach across its external policies would mean for the EU to be more coherent and integrate and coordinate better its diverse forms of external relations. This thesis analyzes if, and under what conditions, the European Union adopts a joined-up approach in its relations with three countries: Israel, Morocco, and Switzerland. The results demonstrate some variation across the case studies. While the analysis reveals that the EU has developed a strong joined-up approach toward Switzerland, there is no indicator of a joined-up approach toward Morocco. Finally, the EU has made several attempts at developing a joined-up approach toward Israel, albeit not in all dimensions of its relations or in a consistent manner. The central thesis of this research is that there is an evolution in the EU’s external action toward a more joined-up approach when it serves the EU’s rational interests.