strategy, approaches to Eastern Europe and Ukrainian security issues, sanctions against Russia, EU missions to Ukraine. The object of the study is to distinguish and reconstruct the most important concepts underlying the security law of the EU, the legal ideology thereof and its implementation in the situation of Russian-Ukrainian armed conflict. The same way, the study provides a new key to understand the principal conceptual transformations of the international security law. The study shows that EU has implemented a wide range of non-military peacekeeping / anti-crisis instruments of its foreign policy in response to Russia’s armed aggression against Ukraine, in particular, political, diplomatic, economic, trade, civilian operational. And they should not be derogated. But, given the general features of the development of the Union’s foreign and security law and policy, there is no reason to expect that the Union will play a crucial role in restoring Ukraine’s territorial integrity. Instead, as the authors propose, the intentions, potential and tools of the EU’s “soft power”, including the potential of two functioning EU missions, should be fully exploited to de-escalate the crisis, enhance the resilience and economic development of the Ukrainian state, and manage conflicts in Ukrainian society. That could be the proper way to implement positively the new international security law paradigm potential.