The Ukraine Crisis becomes the “game changer” for the European Union’s foreign affairs and defense policies. In the security and defense area，the crisis has accelerated the feeling of distrust between the EU and Russia. To contain the potential threats trigged by the Crisis，the EU and North Atlantic Treaty Organization（NATO）have strengthened their security schemes and operations. Concerns have also risen as to the energy supply security. Not surprisingly，building an energy union emerges as one of the priorities of the institutional reforms of the new European Commission. As regards the EU’s foreign affairs，its relations with Russia have been dramatically damaged by the Crisis. Under the pressure of the U.S，the EU adopted economic，military and financial sanctions towards Russia，which has made negative impacts on the EU itself. As to the EU-U.S relations，the EU member states took military strikes jointly with the Americans on ISIS terrorism. Both of them improved cooperation on protecting personal information，but divergence still remains between them. In line with the “Agenda for Change”，the EU has taken significant steps to align the development cooperation with its neighborhood policy，particularly the eastern partnerships.