This thesis aims to explain how the Ukrainian army has been able to continue fighting after a surprise. Previous research has not been able to satisfactorily explain how the army could continue to fight after it had been subject to surprise. The theory that this thesis uses is Meir Finkels theory on how to recover from surprise and uses it to study flexibility in the Ukrainian army. The method of this thesis is a theory-consuming case study, and it uses focused, structured comparison to analyze the case. The material that is used in the study is reports and analysis to be able to research the case. The results are that the Ukrainian army has showed that they are flexible to a relatively big extent. But they are not entirely flexible and still have a Soviet heritage that is shown in some cases in the army. The study could therefore observe a correlation between flexibility in the Ukrainian army and that they could continue fighting.