Thank you for proving that you know nothing about the issue before commenting on it. Northern Iraq is where the autonomous Kurdish Regional Government is and they're in cooperation with the Turkish military against PKK in these operations. Sometimes they take part in them or share intelligence mutually. Turkish military has trained the military of the region many times against PKK or ISIS. The regional government hates PKK and PKK hates the regional government. They're terrorists and traitors to their own people. Educate yourself. Apart from being legitimate, the operations need to be taken to the bases and caves of PKK, otherwise they penetrate the cities and towns both in Turkey and Northern Iraq, take control of them, extort or kill the locals for supplies and they have a much easier time committing attacks in large cities.