The concept of hybrid warfare is both well used and criticized in today's debate. The critics are several and they do not hold back the criticism. But if the modern war is to be understood, how should it be investigated? When answering that question the critics turn to Carl von Clausewitz theories. The purpose of this thesis is to investigate the explanatory value of Clausewitz Trinity concept and Frank G. Hoffman's definition of hybrid warfare, by examining the theories of Russia's Annexation of Crimea 2014. Thus, this thesis wants to investigate whether Clausewitz Trinity concept is sufficient to understand the case . With a most likely one-case study and with the method of qualitative text analysis, the results and conclusions showed that it is not so easy to claim that one concept can rule out the other.