This book explores varying outcomes of energy cooperation, defined as diplomatic relations, bilateral trade, and investment in oil and natural gas. The book looks at economic potential, geopolitical rivalry, and domestic interest groups in the cases of U.S.-Russia, U.S.-Azerbaijan, and Russia-Germany energy ties. It aims to reveal the interplay of economic considerations, domestic politics, and geopolitical rivalries in energy security. This book utilizes an innovative approach of exploring the dyads of states (bilateral relations), rather than structuring research around the sources of energy (oil, gas, nuclear).