This article presents the origins of and the recent developments in the alliance between Iran, on one side, and Armenian diaspora nationalists and the government of Armenia on the other. The use of Armenian nationalism by Iran started with the first Shah of the Pahlavi dynasty, but the Islamic Republic of Iran developed and intensified those ties. Building on the success of Azerbaijan in the April conflict of 2016, the liberation of its previously occupied territories in 2020, the full reconstitution of the Türkiye–Azerbaijan– Israel triangle, and the weakening of Russia since 2022, this article explains the reinforcement of the ties between the partners and the unprecedented rise of Iranian aggressiveness against Azerbaijan.