Surprise as a method for achieving success in combat has been a key factor since the dawn of warfare. This study has analyzed what key factors are needed to achieve strategic surprise by examining existing theories on the subject by applying them on two strategic surprise operations during the second World War. The study has combined several of the best known military theorists understanding of surprise to an analytical framework that was applied to the two cases. The results show that existing theories on surprise has the ability to explain how strategic surprise is achieved but not all given indicators were met. Deception, secrecy, originality and speed was shown to be the four key factors needed. Planning and implementing these factors during the operation will increase the chance of achieving strategic surprise and prevent the enemy from detecting and successfully deploying its troops to intercept the incoming offensive.