By Fang Xiaozhi

At 7 a.m. n February 1, the United Kingdom (UK) officially announced its withdrawal from the European Union (EU), becoming the first country in history to leave the EU. The UK and EU will enter into a transitional period in the following 11 months, during which they will conduct negotiations over the development of their future relations and cooperation. The successful Brexit is surely to deliver greater impact on the process of EU defense integration, and also to make the UK-EU defense cooperation more complicated in the future.

For the EU, Brexit will greatly promote its defense integration in a comprehensive way. Creating a common defense system for the EU is a great dream for many Europeans who are unwilling to be "slavishly dependent on the NATO". However, due to the consideration of leveraging NATO to maintain its position in the EU, the UK has always been an opponent to EU defense integration, and repeatedly blocked the development of the EU defense system. In addition, France and Germany, as the two cores of the EU, have always displayed greater willingness to jointly develop weapons, such as the fifth-generation stealth fighter in Europe. However, the project has just been put aside due to the repeated obstruction from the UK.

The Brexit will definitely further impair the EU's overall defense capabilities. What’s worse, the United States has threatened to reduce its security commitments to NATO European countries. As a result, the EU has to promote even closer cooperation in defense. Recently, some EU member states with expectations for a common defense policy stated that without the constraints from the UK, the defense integration process will likely achieve new breakthroughs, and they are greatly encouraged by this.

The more profound significance of Brexit for the UK government is that it can re-examine its international status and thereby make adjustments, so as to strike a balance between maintaining national sovereignty and participating in EU’s decision-making to the full extent.

The UK-EU relations have entered into a transition period after Brexit, during which the free exchange of people from both sides will remain unchanged for the time being, and the UK will continue to follow a majority of the EU rules for the rest of the year. All these serve as positive conditions for the two sides to maintain cooperation. Moreover, the UK has been involved into the EU for nearly half a century. Despite the differences on many issues, they still share many interests. Their interdependent defense and security relationship stays firm with a broad base of cooperation, especially for such issues as international arms control, Iranian nuclear deal, and NATO’s mutual defense, where the UK stands even closer to the EU compared with the United States.

In particular, since Donald Trump takes office, the US administration announced to raise the security threshold for US allies, giving birth to a series of new challenges to European countries. Therefore, the need for the UK-EU interdependence stands even more apparent.

In short, due to the constraints of national interests and the influence of various international and domestic factors, the development of the UK-EU defense cooperation is sure to face great challenges in the future. The post-Brexit defense and security relationship between the UK and the EU will continue to exist but with changes. The pragmatic policy will have a particularly significant impact on the concept of the UK’s participation in the EU defense and security cooperation.

On the one hand, the UK is confronting an increasing number of more complex security challenges, and needs to work closely with the EU countries to safeguard its own security interests. On the other hand, the UK is declining in strength, while still eager to exert its defense and security nfluence in Europe and even the whole world to maintain its national status. Therefore, the UK government is likely to continue its pragmatic strategy in the future, adopt a more flexible approach, pay more attention to the cost efficiency of defense and security cooperation, actively defend national interests, and strive to exert its own security influence.

In a word, Brexit will not bring substantial changes to the UK-EU defense and security relationship, and there will be no major changes in the general direction of their defense and security relationship in the future. A more flexible and dynamic approach in cooperation will be the ultimate result pursued by both parties.

(Fang Xiaozhi, a researcher at the BRI Institute of Strategy and International Security, Fudan University)