The Revolutionary Guards initially kept quiet about their role in the Syria conflict. But in recent years, as casualties have mounted, they have been more outspoken about their engagement, framing it as an existential struggle against the Sunni Muslim fighters of Islamic State who see Shi'ites, the majority of Iran's population, as apostates.
The Guard formed out of Iran's 1979 Islamic Revolution as a force meant to protect its political system, which is overseen by Shiite clerics. It operated parallel to the country's regular armed forces, growing in prominence and power during the country's long and ruinous war with Iraq in the 1980s. It runs Iran's ballistic missile program, as well its own intelligence operations and expeditionary force.