The European Union’s joint security and foreign policy towards Russia has gone through numerous unwanted ups and downs after the collapse of the Soviet Union, especially over the last two decades, due to various reasons although during the post-collapse conditions hopes for integration of Russia with Europe had been strengthened. Some causal premises are more important in this regard such as complexity of relations from a historical standpoint, the impact of contradictory norm-value sources on the EU’s decision-making  towards Russia, lack of sanctions  of the enactments of the EU in the security and foreign policy area, priority of a national policy  and lack of consistency among the members in implementing the decisions, conflicting multifaceted political, military and security conditions and in the end, mutual dependence, especially in the energy sector. Considering the above-mentioned concepts, the question of this paper is that “why the European Union’s joint security and foreign policy towards Russia has had serious changes and vacillations  after 2000?” the primary response is that the European Union’s joint security and foreign policy has been, on one hand, under pressure from geo-political considerations and energy security for cooperation with Russia, on the other hand, has been under the impact of practical inconsistency in this sector among the EU members and necessity of adopting  a confrontational policy against the Russian dominance to remove the regional worries, and this has made the European Union’s joint security and foreign policy towards Russia vacillate. The method used in this paper is of Analytical-Qualitative type.