Kurdish nationalism in Iran is quite weak currently compared to the bright days in the last century, largely due to strength of the Iran, as well as Iran's relations with regional Kurdish organizations. Iran, through its relations with the Iraqi Kurdistan Democratic Party, the Patriotic Union of Kurdistan and the PKK, prevents these organizations from supporting the Iranian Kurds or manipulates these organizations against its own Kurds. Linguistic and sectarian diversity and the population structure of the Iranian Kurds foster the weakness of Kurdish nationalism. While overlapping Sunnism and Kurdishness strengthens Kurdish identity in Iran, Shiism weaken Kurdish identity among Shiite Kurds and prevents them from participating Kurdish movement. Indeed, the support of Sunni Kurds for Kurdish nationalistic organizations is far stronger than Shiite Kurds. Shiite Kurds, who have a high level of integration into the Iranian system, stay away from Kurdish parties and participation in Kurdish organizations remains marginal among Shiite Kurds. This phenomenon makes Kurdish organizations largely Sunni organizations. In addition, low population growth rate of the Iranian Kurds is another weakness of the Kurdish movement. Most of Kurdish majority areas suffers from low fertility rate which is even below the replacement rate. Low natural population growth rate in Iranian Kurds will weaken the Kurdish movement in Iran in the long term. On the other hand, the natural population growth rate is still high in some regions in which armed militant groups recruit young Kurds in high number.