The article analyses the consequences of the withdrawal of the United Kingdom from the European Union, particularly the political effects of its decision. In the first place, it addresses the holding of the referendum, and the decision to withdraw, as a paradigmatic example of the so-called “new politics” that has given special prominence to the so-called populist forces in Western societies. Then, the peculiar negotiation between the UK and the EU to establish a withdrawal agreement is examined. Next, the different forms of commercial ties that the EU currently maintains with third States are identified as a reference to the agreement that may be established with the United Kingdom. Finally, the viability of the Global Britain project as a future strategy to regain a position of international influence is evaluated. The conclusion reached is the paradox that Brexit represents, as the United Kingdom has launched a traumatic, uncertain and divisive process to achieve an international, political and commercial position, which in objective terms will be indisputably worse than the one it left.