Until early 2015 most Kurdish armed groups officially discouraged foreign volunteers. In most of the world foreigners fighting with the Kurds is illegal and the Kurds don’t want to get into trouble with their foreign donors. Because of political problems with the Iraqi government (who don’t like the Kurds up north being autonomous) the Kurds get few military supplies from Iraq. Instead Western nations quietly fly in weapons and ammo. But there are strings attached to this aid and one of those strings prohibits foreign volunteers.
Despite this over a thousand foreigners have gone to Iraq to volunteer and the Kurds eventually figured out how they could use these foreigners without endangering their foreign aid. First, they found support jobs the foreigners could do. This ranged from security to training and technical support. Many of the foreigners had technical skills and most had military experience. By mid-2015 many of the official military advisors (mostly from NATO nations) helping the Kurds convinced their governments to ease up on the prohibitions on “mercenaries” fighting with the Kurds. Thus was established an unofficial deal that allowed the Kurds to make use of the foreigners. Those with the most military skills were sent to fight in small units, usually of mostly foreigners. Particularly useful were foreigners with sniper experience. Some of these men managed to get sniper rifles and soon proved very useful. Most of the NATO veterans also had medical experience. Not so much as doctors or technicians but as combat medics. Most American combat troops have received a lot more medical training since 2003 and can serve as front line medics. Some of these men have contacts back home who can obtain and ship medical supplies needed by frontline medics. Some veterans have UAV experience and a few have brought commercial UAVs with them. Other Western veterans have communications experience and access to commercial radios that serve as effective substitutes for military radios.
All of these foreign volunteers are eager to teach Kurds their skills and the Kurds as quick to learn and absorb these skills. Many Kurds speak some English and the volunteers are willing to learn as much Kurdish as they can. Some of the older veterans who volunteer are persuaded to spend most of their time training or advising. Some of these volunteers had served that function in Iraq and Afghanistan when they were still in the military. By late 2015 these new rules and how they worked had spread to Internet locations where potential volunteers go to find out how to help. This makes the process of volunteering less chaotic and more useful for all concerned.
One things the volunteers have to learn is the unique position the Kurds occupy in Iraq and the Middle East. Since 2003 nearly all the violence you heard about in Iraq was in Sunni Arab areas of central Iraq and the Shia areas where the Sunni Islamic terrorists would make so many of their bombing attacks against civilians of all sorts (pilgrims, women, children) as long as they were Shia. Meanwhile the north has always been so peaceful that Western journalists, and just about anyone else, could move about freely, without fear of attack. How could this be?
Well, for one thing, the Kurds have tight controls on their borders and any Arabs entering are checked carefully. Arab Iraqis are welcome to visit, and many do, for vacations from the violence in the south or to do business (sometimes to meet with foreigners uneasy about coming to Baghdad). When asked, Kurds attribute their peaceful neighborhood to the fact that Kurds are not Arabs. But this is not the main reason, for the Kurds have, in the past, been as factious and violent as the Iraqi Arabs are now. It was during the 1990s, when the U.S. and Britain agreed to keep Saddam's forces out of the north (to prevent another large scale massacre of Kurds), that the Kurds sensed a rare opportunity and sorted out their differences and learned the benefits of cooperation, rule of law and civil order. In effect, the Kurds had a ten year head start on the rest of Iraq in the "how to create peace and democracy" department. The Iraqi Arabs, Sunni and Shia, who come north on business, or for a vacation, note this. The Arabs believe they are superior to the Kurds ("a bunch of hillbillies," to most Arabs), and find it irritating that the Kurds have made things work, while down south, especially in central Iraq, things are still a mess. Given time the Iraqi Arabs will probably catch up. But this is not a popular solution to the "Iraq problem," and no career-conscious journalist is going to talk about what the Kurds have done and why the Arab’s haven’t.