The aim of this article was to identify threats created by the Republic of Belarus in the context of the migration crisis and their impact on Polish security. In the process of developing the article, by means of the method of critical analysis of the literature, it was determined that the essential conflict on the Polish-Belarusian border should be evaluated in a broader political context. The aim of the Belarusian regime’s actions was to soften the EU policy, weaken the internal opposition and legitimization of power by other states. By using migrants, Belarus, through coordinated actions with the Russian Federation, seeks to put pressure on states that have been most vocal in their support for tougher sanctions. By making Belarus politically and militarily dependent on itself, Russia actively influences other actors in the international security environment, primarily Poland, but also NATO and the EU. It is assessed to be testing the resilience of the eastern flank states, primarily Poland, as well as testing the reactions of NATO and EU member states to elements of a hybrid conflict. The article presents military and non-military threats created by Belarus, as well as conclusions and recommendations to enhance the security of Poland.