This article analyses international law norms and diplomatic mechanisms concerning militaryexercises. As such a topic is relatively new, with the international legal system being breachedby authoritarian regimes using lawfare, the legal aspects of military exercises have not yetbeen researched and thus require more focus, especially from the standpoint of hybrid threats.International law itself is leaky and lacks enforcement measures, since sanctions are not anelement of the international legal arrangement. It lacks a centralised enforcement mechanism,the principles and rules governing responsibility for wrongful acts require the wrongdoerscooperation, and the mechanisms and procedures to deal with the consequences of suchwrongful acts, including restitution and compensation, are not universally recognised. Mostcountries in the global arena follow the paradigm of the United Nations, where states mustmaintain their relations in a peaceful manner in order to achieve security and stability. However,some undemocratic states, mainly the Russian Federation and the Peoples Republicof China, have been presenting hostile postures towards the Western worlds values, wherehuman life tops the hierarchy of protected values. Traditionally, military exercises have beenused as a messaging tool between strategic competitors and potential adversaries to signaltheir own military strength. Russia and China are fully aware of the lack of hard law concerningthe subject of military exercises; they readily seize the resulting opportunities to create andexploit legal grey zones, as well as to frequently breach international law, while knowing thatlittle can be done against their malevolent conduct.