This chapter lays the groundwork for the book's main theme: the changes in the geopolitics of natural gas in the Eastern Mediterranean following Russia's 2022 invasion of Ukraine, and the European Union's efforts to reduce its over-reliance on Russian gas and diversify its supply sources. The first chapter also outlines the author's methodology, beginning with the research question: To what extent are European energy policies reshaping Israel's geopolitical influence in the Eastern Mediterranean? It then leads to the hypothesis the author seeks to test: that redirecting European gas demand could strengthen Israel's position as a key player in the regional energy system, potentially exacerbating geopolitical tensions in the Eastern Mediterranean. The chapter further demonstrates the selection of the regional security complex theory as the appropriate conceptual framework for interpreting the new energy security dynamics in the Eastern Mediterranean, particularly given the prominence of energy security on the political agendas of the region's states.