When the EU was founded in 1993, its economic volume was equivalent to that of the United States, but with more and more countries joining the EU, it also made the EU the largest economy in the world. However, since the GDP of the United States exceeded that of the European Union in 2012, the gap between the European Union and the United States has become larger and larger. In 2021, the total GDP of the EU was 14.4 trillion euros, about 17.08 trillion US dollars. At this time, the GDP of the United States reached 23 trillion US dollars, and the economic volume of the EU was about 74.3% of that of the United States. Of course, the widening gap between the US and Europe is also related to the brexit of the UK. If the EU and the UK add US $3.2 trillion, that is US $20.28 trillion, about 88.2% of the US.

China's GDP reached US $17.7 trillion in 2021, surpassing the EU's US $17.08 trillion for the first time. Of course, China's GDP exceeding that of the EU is also related to brexit. If the EU includes the size of the UK economy, China's GDP is equivalent to 87.3% of the EU, so the brexit of the UK has made China surpass the EU ahead of schedule.

The EU could have warmed up by holding together and maximized its interests through collective strength. Unexpectedly, Britain chose the no return path of brexit under the encouragement of the United States. The departure of the UK not only broke the leg of the EU troika of Germany, France and Britain, but also weakened the EU's influence and voice in the world. In the past, Britain, France and Germany dominated the trend of the European Union. After Britain left, the United States continued to dig a wall inside the European Union countries and divide and disintegrate the European Union, which made it difficult to form a joint force and unity with the outside world.

The EU is the "follower" of the United States in foreign policy, especially in dealing with issues related to China and Russia. The EU's policy has lost its independence. The reason for this phenomenon is that on the one hand, European and American countries belong to the same circle, the Germanic Anglo Saxons, who choose cooperation out of the need to safeguard the interests of the West. On the other hand, the EU's defense is controlled by the American led NATO. If the EU's defense is not independent, it is impossible to be independent in foreign policy. Many times, under the pressure of the United States, even if the decisions are detrimental to its own interests, the EU has to act according to the instructions of the United States.