共同防務是歐盟發展較為緩慢的政策領域。雖然歐盟陸續透過CFSP和CSDP促進共同防務的制度化合作，卻還是難以化解外界對其「經濟巨人，政治侏儒，軍事小蟲」的批評，因此2016年提出的歐盟全球戰略(EUGS)深具象徵意義。其中德國身為歐盟最富有的國家，長期以來「重經濟而輕軍事」，也在2016年正式表態承擔共同防務領導責任，被視為一種典範轉變。本文以穆拉維斯基的自由政府間主義檢視歐盟防務整合的發展，並從「利益」與「權力」因素解釋德國對共同防務的偏好形成以及在歐盟政府間談判的角色。本文認為德國對共同防務的積極表態與歐洲近年來面臨的地緣政治環境挑戰有關，德國的變化有助於共同防務發展，但是從部分會員國對PESCO和EI2的顧慮來看，廣度整合與深度整合的分歧仍然無解，強調盡可能擴大參與的「包容性原則」雖然可降低德國遂行獨斷獨行領導風格的可能性，長久來看卻不利於化解分歧或產生共識。

Compared to other policy areas, the integration of common defence in the EU is happening at a rather slow pace. Although member states have been encouraged to engage in the institutionalised cooperation of common defence via the CFSP and the CSDP, the EU was hardly able to get rid of the image of being ‘an economic giant, a political dwarf, and a military worm’. The launch of the European Union Global Strategy by the European Council in 2016 is therefore considered to be an ambitious manifesto for promoting further defence integration. On the other hand, Germany, as one of the wealthiest countries in the EU, for a long time kept a distance from engaging in out-of-area military operations but published a new white paper on security policy in 2016 promising to take more responsibility in leading common defence. This ambitious movement is appreciated as ‘a paradigm shift’. To explain this development, this article applies the analytical framework of liberal intergovernmentalism to explore how the factors of national interests and power affected the formation of German preferences and the engagement of the intergovernmental bargain at the EU level. The author argues that the paradigm shift of Germany on the security policy is to respond to the increasingly serious geopolitical challenges since the 2010s, and it is favourable for further defence integration. But the concern of some member states about the PESCO and EI2 reminds us that the divergence between inclusive equilibrium and great convergence is still unresolved, and insisting on the principle of inclusive equilibrium, nevertheless, is not conducive to overcoming divergences.