In comparison with their brethren in Iraq, Syria, and Turkey, you rarely hear much about Iran’s Kurdish population, but in terms of sheer numbers (i.e., not as a percent of their country’s population) there are more Kurds in Iran than in Syria and maybe even in Iraq (estimates aren’t very consistent and there’s probably some cross-border back-and-forth that would affect any count). Also, there are closer affinities between Kurds and Iranians than between Kurds and Turks or Arabs. Kurds are deeply rooted in Iranian history, particularly if it’s true, as most Kurds believe, that they’re descended from the ancient Medes, who ruled much of the area that’s now modern Iran before the Persians overthrew them in the 6th century BCE. Later on, the 16th-18th century Safavid Dynasty, which can be considered the progenitor of modern Iran in many ways, may have been ethnically Kurdish or at least part Kurdish (yes, I know Saladin was also Kurdish, but his impact on Egyptian history was much less profound than the impact the Safavids had on Iranian history). Also, Kurdish is an Iranic language family, contrary to whatever “Mountain Turks” line of BS you might hear to the contrary.
The reason you don’t hear very much about them is because, generally speaking, Iranian Kurds have been the only large regional Kurdish population that isn’t either engaged in open warfare (as Syrian and Turkish Kurds are) or that has achieved a degree of national autonomy…and is engaged in open warfare (as Iraqi Kurds have done and are). But they used to be. Iranian Kurds spent most of the 20th century either agitating for separation from Tehran or outright revolting (remember the ill-fated Republic of Mahabad?). Many Kurds eagerly participated in the 1979 revolution against the Shah, only to get treated just as badly by the new Islamic Republic (particularly Sunni Kurds, who were treated as something of a potential fifth column and lost many of their rights under the IRI along with every other Iranian Sunni), but in the 1990s things in Iranian Kurdistan started to calm down.
Part of this was thanks to Mohammad Khatami, who as president appointed an actual Kurd as the governor of Kurdistan province and named several Kurds either to his cabinet or as top advisers. But part of the shift was also due to events in Iraq. As Kurds there began to gain autonomy, first under American air cover and then following the US invasion of Iraq, Kurds in Iran toned down their own struggles, and the main Kurdish militant party in Iran, the Kurdish Democratic Party of Iran (KDPI, which traces its origins back to that Republic of Mahabad), mostly relocated to Iraq and stood down. But last year the KDPI reportedly started moving back across the border, into Iran, and then in the middle of June, this happened:
On June 15, news came out of the Iranian town of Shino, a Kurdish city in western Iran, that an armed group had clashed with the Islamic Revolutionary Guard Corps and that both sides lost six fighters. The armed group was soon identified as peshmerga fighters who belong to the Kurdistan Democratic Party of Iran (KDPI). Reports claimed further clashes in many towns in the area, including Piranshahr.
Iran responded by shelling the KDPI camps along the border.
More clashes between the KDPI and Iranian forces took place in Mahabad about a week and a half later.
I’m overselling the extent to with Iran hasn’t been dealing with Kurdish separatist violence, but the KDPI really has been mostly quiet for the past 20 years and they were/are the largest Iranian Kurdish militia. There is another group, the leftist Kurdistan Free Life Party (PJAK) that has been more consistently at war with the Iranian government over the past decade or so, but PJAK (and its militia, the East Kurdistan Defense Units or YRK) is much newer than the KDPI so it’s hard to gauge how deep its support runs. PJAK has also been quiet recently, since 2011…or rather it had been quiet. Its fighters appear suddenly to have started getting into shooting matches with Iranian forces as well.
What’s causing the sudden uptick in Iranian Kurdish violence? It probably depends on whom you ask:
What prompted the KDPI’s sudden change in course? Most people believe that regional countries or global powers are behind the resurgence of the Kurdish activity. Iranian-Kurdish political activist Hadi Azizi believes the KDPI is engaged in legitimate self-defense against Iran. He told Al-Monitor that he does not believe that external elements were instigating these attacks, saying, “No doubt Iran doesn’t have a major say in Middle East politics. They don’t always have the support of international powers. Iranian Kurds are ready to rise.”
It’s certainly possible that some foreign support, say from the Saudis just hypothetically, has found its way to the KDPI in return for the organization resuming some kind of violent campaign against Tehran. But it’s also true that the regional stature of the Kurdish people hasn’t been this high in decades, if ever. The Kurdistan Regional Government mostly controls northern Iraq. Kurds in Syria have carved out their own de facto state. Kurds in Turkey are once again suffering because of fighting between the PKK and Ankara, but before the fighting really kicked back into gear the predominantly-Kurdish HD Party was establishing itself as a genuine force in whatever is left of Turkey’s democracy. So you can see where Iran’s Kurds might see this as the time to stake their claim to Kurdish territory in Iran, as well, part of a regional pan-Kurdism, if you like.
The problem for the KDPI is that there is no regional pan-Kurdism. The KRG and the PKK (and therefore also the PKK-linked YPG in Syria) mostly hate each other at the leadership level, going back to a Kurdish “civil war” that the two groups fought in the 1990s (the KRG was known as the Kurdistan Democratic Party or KDP back then), when the KDPI fought with the KDP and against the PKK (PJAK, on the other hand, was formed from the same Kurdish union to which the PKK and PYD belong, and some observers argue that the three groups are really all one big group). The KRG has pretty good relations with Ankara (it sells oil via a pipeline into Turkey), which only exacerbates the tension between it and the PKK. The KRG also has pretty good relations with Tehran and there’s been talk of building an oil pipeline for KRG-controlled oil running through Iran to go along with the one running through Turkey. So there’s pretty likely to be a limit as to how willing the KRG will be to keep hosting a large portion of the KDPI’s membership if the KDPI really decides to go to war with Tehran. PJAK has those close ties to the PYD and PKK, but both of those groups kind of have their hands full right now.