A recent video published by the PKK's Syrian offshoot the People's Protection Units (YPG) showing foreign nationals vowing to fight in the terrorist group's ranks has once again pointed to an issue that has played a significant role in conflicts devastating entire countries in the Middle East.

In a video posted on Youtube Monday by an account called the "YPG Press Office," six people dubbed as "International Volunteers" claim that they will be fighting in Afrin as part of an alleged battalion, named after one of the dead militants of either the YPG or the PKK terrorist group's armed wing the People's Defense Forces (HPG), who was described as a "martyr."

One person acting as the group's spokesperson, apparently an American as his accent gave away, says that they have been fighting alongside the terrorist group, which he describes as 'Kurds as a whol'e despite various Kurdish political factions, against Daesh terrorists. He adds that for Turkey's long-expected operation in Afrin, they have been trained and equipped by the YPG, the dominating group in the U.S.-backed Syrian Democratic Forces (SDF).

One of the foreign fighters that appears in the video is 24-year-old British-Chinese fighter from Manchester, known as Huang Lei, the BBC reported. He went to Syria in 2015 to fight Daesh, and there are currently two other U.K. nationals in the group that are poised to go to Afrin, the report said.

Although the video is new, the notion of foreign fighters rushing to their "holy" causes in the six-year-long Syrian civil war is not. A U.N. report in April 2015 had estimated that more than 25,000 people were fighting in the ranks of various terrorist and armed groups in conflicts in Ukraine, Afghanistan, Southeast Asia, and Africa with the vast majority arriving in the Middle East.

Amid decade-long invasions in Iraq and Afghanistan, topped by discrimination, poverty and Islamophobia in their countries of origin, most of these fighters have been radicalized Muslims from Europe, Russia and relatively stable countries in the Middle East, joining Daesh and al-Qaida terrorist groups. Especially for Daesh, foreign fighters estimated as high as 20,000 formed the bulk of the terror group's fighting force, with a U.S. intelligence estimate in early 2017 stating that at least 40,000 people from 120 countries arrived in Syria and Iraq to fight for the terrorist group. Since these fighters had no local ties, no past and no future in the region except for their distorted ideology rejected by almost the entire Islamic world, they committed the worst atrocities in the Syrian civil war and facilitated the group's later expansion to northern and central Iraq, which have also contributed to its initial success and collapse of entire army divisions.

While many have baselessly accused Turkey of supporting Daesh and the Nusra Front terrorist groups, the country has been very active in fighting both organizations. So far, Ankara has deported more than 5,000 Daesh suspects and 3,290 foreign terrorists from 95 countries and has dismantled several terrorist cells that provided logistical assistance in Syria and Iraq, as well as those who plotted attacks inside the country. In addition, some 55,000 foreign nationals were banned from entering the country, despite poor cooperation by other countries. Turkey, the only foreign country that has actively fought against Daesh on the ground, become one of the primary targets of the terrorist group in a string of deadly suicide attacks.

So far, many experts and politicians have claimed that their countries of origin have allowed foreign fighters to depart for elsewhere to effectively get rid of them and not deal with any investigations or judicial processes, instead of killing them in combat zones. The fate of most Daesh-linked fighters remains unknown, a large portion of which are believed to have died as Daesh was defeated and kicked out of almost all the territory controlled – larger than Britain at the height of the 2014 blitz in Iraq in Syria – throughout 2017. Some have managed to leave battle zones, with even a smaller portion getting arrested back in their countries of origin. However, two evacuation deals by two different and competing powers have raised eyebrows. While the Russia-backed Assad regime allowed Daesh fighters to leave their exclave near their border with Lebanon for eastern Syria in August, a similar deal involving thousands of militants was struck with the U.S. backed Syrian Democratic Forces (SDF) in Raqqa, once dubbed as Daesh's capital, in October.

The fate of the militants evacuated from Raqqa is also a mystery, but President Recep Tayyip Erdoğan said Wednesday that Turkey has information about the YPG, information which involves keeping some of these fighters to possible use them in the future in different places, including Afrin. Turkish media has also reported that some 300 male fighters and their families that fled from Mosul were brought to Afrin. In a previous statement, Erdoğan had also pointed to the rise of terror attacks in Egypt's Sinai peninsula, saying that the mercenaries that used to ravage Syria and Iraq are now being deployed to the restive area.

The atrocities Daesh committed against its opponents, people who rejected or ignored its codes of daily life or non-Muslims, especially against Yazidis in Sinjar in the summer of 2014, prompted a global outcry. It was around the same time when the YPG, confined to its enclaves handed over by the Assad regime – a longtime PKK ally to harass Turkey and keep its power balance – in the early stages of the civil war, began to confront Daesh since the moderate Syrian opposition, facing attacks from both the regime and terrorist groups, as well as Iraqi government forces, collapsed, leaving the Kurdish Regional Government's Peshmerga units and the PKK as the only forces battling Daesh in northeastern Syria and northern Iraq.

The PKK is already being recognized as a terrorist group by Turkey, the U.S., EU and NATO, however, this has not stopped the U.S.-backed coalition from supporting the group with arms, ammunition, air strikes and training. While the U.S. has some of its key allies in the region, including Turkey as the closest country to combat zones, it went on to prefer the YPG as its ally on the ground in Syria, straining ties with Ankara while further alienating Sunni Arabs, leaving another grievance between local elements.

Despite its feudal ties, heavy reliance on support from NATO-allied countries, and the political and economic oppression of locals -since the PKK claims that it is a Marxist group with its sympathizers and backers coming from leftist movements around the world - foreign nationals started to appear in the ranks of the PKK and its affiliates. This flood of volunteers supposedly bears resemblance to the "International Brigades," the volunteers who fought for the Spanish Republic against Nationalists during the Spanish Civil War between 1936 and 1939, at a time when fascism and Nazism was on the rise globally.

However, it should be noted that the group they fought alongside with was involved in a bloody war with Turkey for the last 40 years, leading to the deaths of some 40,000 people in attacks on security forces using guerrilla tactics, massacring civilians, murdering its political opponents and carrying out suicide attacks and bombings attacks on cities. Throughout its affiliates, the PKK also wages wars in Turkey's neighboring countries depending on its regional alliances. This wide spanning network in Middle East, along with a large presence in Europe, makes the terrorist group one of the primary actors in the trafficking of drugs, arms and people between the regions.

While Daesh's brutal atrocities spoke for themselves during their portrayal by the media, participation to the YPG has been promoted almost, with people fighting alongside the group being portrayed as freedom fighters, defenders of locals and minorities, or champions of human rights.

The YPG's ongoing grave human rights violations against unaffiliated Kurds, Arabs, Turkmens or Christians were largely ignored, the U.S.' ongoing support to the group quickly swelled the number of foreign fighters in the group, which is now estimated as high as 7,000, well-equipped militants, with some having been trained in battlegrounds for years.