The UK, having left the European Union, announced the transition to a sovereign foreign policy that implements national interests, which, at the same time, correlate with the interests of its closest allies, primarily the USA. This transition was embodied in the concept of “Global Britain.” It means the country’s presence in different regions of the world, justified primarily by security issues. For this reason, it is necessary to study the British post-Brexit security strategy papers in order to uncover all aspects of the concept and understand how it affects the international system as a whole. The author comes to the conclusion that the implementation of the idea of “Global Britain” contributed to the intensification of the country’s foreign policy made it possible to form new alliances, strengthen the old ones, redirect significant funds for the modernization of weapons, and develop AI in the armed forces. Indeed, this activation was accompanied by the assertion of global security objectives to protect the nation, which turned the concept of “Global Britain” into the central strategy of Britain in the post-Brexit state.