The People's Defense Units, Kurdish abbreviation YPG, also called People's Protection Units, was a libertarian socialist Kurdish militant group in Syria and the primary component of the Syrian Democratic Forces (SDF).
The YPG mostly consisted of Kurds, but also includes Arabs and foreign volunteers; it was closely allied to the Syriac Military Council, an Assyrian militia. Formed in 2011, it expanded rapidly in the Syrian Civil War and came to predominate over other armed Syrian Kurdish groups. A sister militia, the Women's Protection Units (YPJ), fought alongside them. The YPG was active in the Autonomous Administration of North and East Syria (Rojava), particularly in its Kurdish regions.
In early 2015, the group won a major victory over the Islamic State (IS) during the siege of Kobanî, where the YPG began to receive air and ground support from the United States and other Combined Joint Task Force – Operation Inherent Resolve militaries. Since then, the YPG primarily fought against IS, as well as on occasion fighting other Syrian rebel groups and the Turkish Armed Forces. In late 2015, the YPG became part of the SDF, an umbrella group intended to better incorporate Arabs and minorities into the war effort. In 2016–2017, the SDF's Raqqa campaign led to the liberation of the city of Raqqa, the Islamic State's de facto capital. Several western sources have described the YPG as the "most effective" force in fighting IS in Syria.
According to Turkey and Qatar, the YPG is a terrorist organization due to its association with the Kurdistan Workers' Party (PKK), which is listed as a terrorist organization. The flag of the YPG is also a banned symbol in Germany as per Strafgesetzbuch section 86a, although the organization itself is not recognised as terrorist. The Turkish terror classification is not shared by key international bodies in the fight against the Islamic State in which the YPG takes part. Due to this Turkish view, US Army Special Operations Commander General Raymond Thomas suggested the YPG to change their name, after which the name of the Syrian Democratic Forces (SDF) was founded.
Kurdish activists attempted to unify themselves following the 2004 Qamishli riots. The riots began as clashes between rival football fans before taking a political turn, with Arab fans raising pictures of Saddam Hussein while the Kurdish fans reportedly proclaimed, "We will sacrifice our lives for Bush". This resulted in clashes between the two groups who attacked each other with sticks, stones and knives. Government security forces entered the city to quell the riot, firing at the crowds. The riots resulted in around 36 dead, most of them Kurds.
They did not, however, emerge as a significant force until the Syrian civil war erupted in 2011.
The self-defence committees that were to become the YPG were formed in July and August 2011 as the Self Protection units (YXG).
Existing underground Kurdish political parties, the Democratic Union Party (PYD) and the Kurdish National Council (KNC), joined to form the Kurdish Supreme Committee (KSC) and established the People's Protection Units (YPG) militia to defend Kurdish-inhabited areas in northern Syria, i.e. Syrian Kurdistan and the Kurdish enclave of Sheikh Maqsood in Aleppo. Originally a wholly Kurdish force, the YPG began to recruit Arabs from at least 2012.
In July 2012, the YPG had a standoff with Syrian government forces in the Kurdish city of Kobanî and the surrounding areas. After negotiations, government forces withdrew and the YPG took control of Kobanî, Amuda, and Afrin.
By December 2012, it had expanded to eight brigades, which were formed in Qamishlo, Kobanî, and Ras al-Ayn (Serê Kaniyê), and in the districts of Afrin, al-Malikiyah, and al-Bab.
Late 2012: Islamist attacks make YPG dominant
The YPG did not initially take an offensive posture in the Syrian Civil War. Aiming mostly to defend Kurdish-majority areas, it avoided engaging Syrian government forces, which still controlled several enclaves in Kurdish territory. The YPG changed this policy when Ras al-Ayn was taken by the al-Qaeda-affiliated al-Nusra Front. At first the YPG conquered the surrounding government-controlled areas: al-Darbasiyah (Kurdish: Dirbêsî), Tel Tamer and al-Malikiyah (Kurdish: Dêrika Hemko). The subsequent Battle of Ras al-Ayn started in earnest when on 19 November 2012, the al-Nusra Front and a second al-Qaeda affiliate, Ghuraba al-Sham, attacked Kurdish positions in the town. The battle ended with a YPG victory in July 2013.
While many rebel groups clashed with the YPG, jihadist and Salafist groups did so the most often. The YPG proved to be the only Kurdish militia able to effectively resist the fundamentalists. While the YPG protected the Kurdish communities it was able to extract a price: it prevented the emergence of new, rival militias and forced existing ones to cooperate with or join the YPG forces on its terms. This was how the Islamist attacks enabled the YPG to unite the Syrian Kurds under its banner and caused it to become the de facto army of the Syrian Kurds.
2013: Kurdish control of al-Yaarubiyah/Til Koçer
In October 2013, YPG fighters took control of al-Yaarubiyah (Til Koçer) following intense clashes with IS. The clashes lasted about three days, with the Til Koçer border gate to Iraq being taken in a major offensive launched on the night of 24 October. PYD leader Salih Muslim told Stêrk TV that this success created an alternative against efforts to hold the territory under embargo, referring to the fact that the other border crossings with Iraq led to areas controlled by the Kurdistan Regional Government, while al-Yaarubiyah led to areas controlled by the Iraqi central government.
2014: Fight against the Islamic State
In 2014, the Syriac Military Council, a group of Assyrian units, was formally integrated into the YPG's command structure. The inter-rebel conflict during the Syrian Civil War led to open war between the Free Syrian Army and IS in January 2014. The YPG collaborated with FSA groups to fight IS in Raqqa province; the group also formed an operations room with multiple FSA factions, called Euphrates Volcano. However, the general outcome of this campaign was a massive advance by IS, which effectively separated the eastern part of Rojava from the main force of FSA rebels. IS followed up on its success by attacking the YPG and the FSA in Kobanî Canton in March and fighting its way to the gates of the city of Kobanî in September. The actual siege of Kobanî approximately coincided with an escalation in the American-led intervention in Syria. This intervention had started with aiding the FSA against the government, but when the FSA was getting defeated by IS in eastern Syria, it escalated to bombing IS on Syrian territory.
With the world fearing another massacre in Kobanî, American support increased substantially. The US gave intense close air support to the YPG, and in doing so, started military cooperation with one of the factions. While it expected that IS would quickly crush the YPG and the FSA, this alliance was not considered a problem for the US. The YPG won the battle in early 2015.