This book researches positions that national political parties in Germany, France and United Kingdom have toward CFSP. The basis for research present parties' manifestos for the last two electoral periods. Comparison of these documents makes it possible to reveal similarities and differences in partisan stances toward CFSP. The attempt is made to measure the difference between parties' positions. The main aim of this paper is to find out why these convergences or divergences occur. Several hypotheses are made, but only two of them prove to be valid: ideological and historical-cultural. However alone none of these hypotheses is able to produce explanations for the distance between partisan stances. Therefore an attempt is made to combine them and present a joint approach that is able to explain why differences and similarities in parties' positions toward CFSP occur.