Since coastal defense operations tend to fail, this thesis aims to investigate how this type of operation can be more effective and lead to success. The thesis tests two coastal defense theories, developed by Jacob Børresen and Geoffrey Till, on two cases of coastal defense operations by evaluating the validity of the outcomes. Applying the theories as a tool and analyzing the coastal defense operations in the Falklands War in 1982 and Narvik in 1940, a comparative case study is carried out through a qualitative text analysis. The result shows the importance of offensive actions, joint operations and the ability to unity of effort. However, the theories tends to miss important underlying factors and, if the theories are to be used for explaining success in coastal defense operations, they should be further developed.