and left more than 32,000 wounded. in 2011, the obama administration pulled u.s. troops out. isis rushed in. >> the iraqis are paying a great deal for them to be able to cleanse ourselves from isis. oliver: the kurds are the largest ethnic group on earth without a homeland, predominantly sunni, more than 35 million kurds live in iraq, turkey, iran and syria. in iraq, they number about 4.5 million and have their own troops called the peshmerga. despite the site of iraqi army that subjected them to genocide under a brutal tyrant. >> we as the peshmergas, the kurdish people have been the most effective force on the ground stop them, defeat them and break the myth of this organization. >> they have really been holding and gaining the territory against isis. marginalized by the central government in baghdad. iraq's future is complicated.