Objectives:
The purpose of this article is to define the Permanent Structured Cooperation (PESCO) mechanism and to assess its impact on improved security and development of the European Union’s defence capabilities, taking into account the following criteria: time – understood as a justification of the advisability of undertaken actions within the next few years; space – understood as an area in which a given solution will be applied; legal capabilities of enforcing the undertaken commitments; and the impact of Member States’ internal policies on meeting them.

Methods:
Literature query, analysis, deduction.

Results:
Permanent Structured Cooperation mechanism might have a real impact on improved security and development of the European Union’s defence capabilities, provided that all countries participating in PESCO meet the undertaken commitments and implement the projects.

Conclusions:
At the current stage, the Permanent Structured Cooperation mechanism has the potential to have a real impact on the improvement of security and development of the European Union’s defence capabilities. This mainly stems from the will of Member States, which is manifested in the expansion of the number of projects from the initial 17 to 34 planned in November 2018. The thematic scope of the projects and continuous efforts to strengthen the cooperation between EU and NATO. Therefore, it may be expected that if these tendencies continue and the Member States participating in PESCO meet the undertaken commitments and implement the projects, the initiative will be a success – which proves the argument put forward in this paper.