Objectives:
The main objective of this article was to attempt to answer the research question expressed as follows: How does NATO implement the assumptions of the deterrence and defense concept in the context of strengthening the Alliance’s eastern flank?

Methods:
The study employed both theoretical and empirical research. The theoretical research included analysis, synthesis, generalization, comparison, and inference. The leading role in the research process was played by the empirical method, namely a diagnostic survey, within which the technique of expert interviews was used. The main research tool for collecting empirical data was an interview questionnaire.

Results:
The objective of the article — that is, addressing the research problem expressed in the question: How does NATO implement the assumptions of the deterrence and defense concept in the context of strengthening the Alliance’s eastern flank — has been achieved. Each section characterizes and discusses the existing battlegroups on NATO’s eastern flank, their reinforcement, as well as the establishment of new BGs.

Conclusions:
In accordance with the adopted research approach and the author’s capabilities, the remaining directions of change presented in the new DDA concept were described at a high level of generality and require further interdisciplinary research.