Military cooperation between Belarus and Russia is the most advanced bilateral process of integration within the Commonwealth of Independent States. It involves not only the close coordination of the activities of the armed forces but also issues such as the production of military equipment and training of soldiers. At the same time, due to Belarus’ limited financial resources, the role of Russia as a supplier of equipment and sponsor of military exercises is growing. Poland and other Central European NATO countries should closely monitor the deepening military cooperation between Russia and Belarus, while continuing to develop their own capacities and cooperation programs, and seek to maintain the involvement of NATO in the region.