In July 2015, General Qasem Soleimani, former commander of Iran’s elite Quds Force, secretly traveled to Moscow to discuss an emergency plan to rescue the Assad regime in Syria, which had lost control of roughly 80 percent of Syrian territory in four years of civil war. Russia had just helped broker the 2015 Iran nuclear deal, known as the Joint Comprehensive Plan of Action. Soleimani’s trip, disclosed three months later, took place in defiance of UN travel sanctions tied to Iran’s nuclear program and threatened to undermine it. Yet the meeting would initiate a decadelong evolution of the Iranian-Russian relationship, from tactical cooperation in Syria to close partnership today, culminating in the signing of a strategic partnership agreement between the two countries in January 2025.