We have seen in this module that the EU policy process is more complicated than the often cited model of Commission proposals being decided on by the Parliament and the Council. In reality, the EU policy process is characterised by a complex balance between institutions in which the Council is always present and the other institutions have varying degrees of power, depending on the issue in question and in which pillar that issue is dealt with.
It should be now clear the degree to which the EU treaties are central to the decision making process as the entire ability of the EU to devise policy is dependent on there being a remit and a legal basis for EU action in the Treaty on the Functioning of the European Union (and the TEU in the case of the CFSP).
The legal bases contained within these treaties determine who should act in a given circumstance and, by delineating the decision making procedure, they prescribe the degree of supranationalism at play in a given area.
As you will have noted above, the Lisbon Treaty brought in a number of key changes, and increased the supranational nature of the EU by increasing the number of areas covered by the ordinary legislative procedure and incorporating many of the former intergovernmental third pillar (police and judicial cooperation) matters into the more supranational Treaty on the Functioning of the European Union.
That said, some things remain the same. Decision making in CFSP is broadly the same as before (except for the creation of the High Representative) and in its most fundamental aspects, such as the question of unanimity and national vetoes, it remains decisively intergovernmental.