Since the beginning of the 21st century, there has been a noticeable increase in German efforts to ensure security in the Mediterranean Sea. This is part of the growing activities to ensure a strong strategic position in North and West Africa, including the settlement of existing armed conflicts here as sources of threats to instability for Germany and its EU partners. Consequently, Germany found itself increasingly interested in finding reliable strategic partners, one of which is Algeria, which makes the topic of this article relevant. The purpose of the study is to examine bilateral security and defense relations with a special focus on the second half of the 2010s and early 2020s with the help of comparative and event-analysis. Having an applied character, this topic has not yet found detailed coverage in the works of both domestic and foreign, especially German, researchers. The historic background of the German-Algerian dialogue is presented. The growth of high-level contacts in the second half of the 2010s is shown, with Germany having to focus on negotiations with the frequently changing figure of the Algerian prime minister. The article also explores the constraints for the cooperation of German and Algerian armed forces on land and sea, as well as the dynamics of military-technical cooperation. The bilateral cooperation in the resolution of the armed conflict in Mali, first of all, in its northern region (Gao, Kidal and Timbuktu) is considered. The political and diplomatic cooperation on the Libyan track in the middle and second half of the 2010s, as well as shortly after the Berlin Conference on Libya in January 2020, is revealed. In the early 2020s, there was a sharp decline in the intensity and volume of bilateral cooperation in almost all areas. In addition to COVID-19, the importance of domestic political factors and the temporary decline in the practical value of the partnership in Libya and Mali for Germany are stressed. A forecast of the dynamics of bilateral relations is finally given.