The European Council and the Council of the European Union play key ro
les in the European Union.(1) The European Council is largely concerne
d with system-steering, while the Council of the EU undertakes sectora
l policymaking. What is common to these roles is the balancing act car
ried out by both institutions. Both have to mediate the centripetal dy
namics of integration, termed cooperative confederalism here, and the
centrifugal dynamics which are found in the strongly entrenched territ
orial nature of power, centered on the member slates. Using new instit
utionalist analysis, the article illuminates different facets of the t
wo institutions' functioning in mediating the two dynamics.