Kurdish independence

After Iraqi Kurds held an independence referendum last month, the government in Baghdad — which deemed the vote unconstitutional — sent in troops. It wasn't the first time Kurds have pushed toward independence, only to be beaten.

Why it matters: It's likely not the last time, either. The complicated history behind the regional struggle spans across decades and borders, and Kurdish support for independence are coming to a head, not just in Iraq, but in neighboring countries as well.

Spread between four states

The 1923 Treaty of Lausanne left the Kurdish population split between states.

• There are over 2 million Kurds in Syria, 5 million in Iraq, 5 million in Iran, and 18 million in Turkey, per The Economist.
• Between 1991 and 2003, the U.S., Turkey, and Iran pressured Iraqi Kurds to cease calls for independence, fearing the interest would spread throughout the region and cause political chaos. Even now…
• Turkey fears such cascading disruption and has battled its own Kurdish population (in particular the PKK, which it regards as a terrorist organization) for decades.
• Although Iran condemned Iraqi Kurds' referendum, its Kurdish population celebrated in the streets, and calls for independence are growing there.
• Syria, too, rejected the independence vote in Iraq, and has opposed its own Kurdish population's moves towards independence, which bubbled up in 2011.
• Although the U.S. opposed last month's referendum, it played a large role in getting Kurdish status recognized in the Iraqi constitution in the early 2000s. The U.S. draws a line at independence though, in part because it depends on Iraq and Turkey in the anti-ISIS fight.

An Iraqi Kurdistan now?

Iraqi Kurdistan operates has operated semi-autonomously from Iraq's central government, with its own military, government, and foreign policy — it's the closest thing to a Kurdish state in recent decades. That status came as a result of the 2003 U.S. invasion, which toppled Saddam Hussein (who had previously committed genocide against Iraqi's Kurds). The new government formalized the Kurdish semi-autonomous government.

• Clashes since the independence vote this fall: Following the referendum, Prime Minister Haidar al-Abadi said sending in troops to Kirkuk, a region Kurds have held since 2014, was necessary to "protect the unity" of the country. Instead of statehood, the Kurds got a conflict with the potential to erupt into civil war. U.S. Colonel Ryan Dillon said Friday the Kurds and Iraqis had almost reached a cease-fire deal.

The stops and starts for independence

• After the Treaty of Lausanne, an independent Kurdish state was established in Iran, which survived for 2 years with Soviet support.
• Iraq jailed Kurdish nationalists in the 1940s.
• The first Kurdish-Iraqi war erupted in 1961 and lasted until 1970, with the Kurdish Peshmerga soldiers receiving support from Iran. This conflict ended in an agreement that allowed Kurds de facto autonomy and recognized Kurdish as an official language.
• But the agreement fell apart over disputes about territorial ownership of oil-rich Kirkuk, and Iran didn't aid the Kurds due to a deal with Iraq.
• Between 1968-1989 Iraq forcibly evacuated Kurds to settlements in the north.
• In 1988, Saddam responded to an uprising with executions and poison gas attacks.
• In 1991, the Kurds rose up again, and Saddam put them down again. International coalition forces intervened to provide safe havens for the Kurds, and the Kurds set up a government with de facto autonomy.
• The 2003 U.S. invasion toppled Saddam and led to Kurdistan receiving recognition as a federal entity.
• As Iraqi forces fell to ISIS in 2014, Kurds seized oil-rich Kirkuk, which is technically outside of its borders.