Complex sentence: Together with Maria J. Stephan of the U.S. Department of State, Chenoweth co-wrote the book, "Why Civil Resistance Works", which develops the theory of civil resistance and its success rate for political change compared to violent resistance.
Split into simpler sentences: Together with Maria J. Stephan of the U.S. Department of State, Chenoweth co-wrote the book, "Why Civil Resistance Works". They translated the results into a theory of civil resistance and its success rate for political change compared to violent resistance.