1. Power Strugle : just before Ban Ki-moon confirmation, Dervis's name was circulating for the post of Secretary general. When Ba Ki-moon came in office, since his very first day Dervis has only been a source for trouble of Ban Ki-moon. Myriad of controversies and scandals have risen from UNDP in the past two years and Ban Ki-moon's job was to deal with Dervis's problem most of the time.
Recently with the alleged departure of DSG Miggiro, Dervis eyed the DSG post. turkey approached G77 and WEOG to test the waters for a potential candidacy of Dervis for the Nr#2 of the UN.
But Ban Ki-moon is not stupid. The last person on earth he would want close to his office and as his Nr#2 would be Kemal Dervis. The man who run for his job back in 2006 and who has been a trouble maker since his first day in the job, and who has declared his independence from Ban's Secretariat since day one.
Therefore many attribute Dervis's departure to his failed attempt for the Nr#2 job;
2. IMF - with the sexual scandal investigation report expeted at the end of February, and as everyone predicts that current Chief of IMF would be leaving soon after that, many think that the move from Dervis is calculated to replace IMF Chief and become the "reformer of IMF" as many governments want to.
Again this is very remote given Dervis's Turkish nationality. But someone has pointed out that Dervis is not only Turkish. He has also a French Nationality and Passport. Which might give him the needed push to get the job.
3. Skin cancer - Dervis was operated with skin cancer in his face back in March 2007 and has repeatedly been going back to hospital for treatments in his face and neck and lower back side of his head and left ear. Some in his office attribute the latest resignation as an attempt to give a full time treatment and deal with his cancer.
Strange that a social-democrat like Dervis resigns just a week before the new US administration comes in. Either he got a negative signal from them, or he got a promise for a higher job somewhere else. Will have to wait and see.
One thing is for sure, his "repatriation grant" in the system is recorded as "WASHINGTON DC", making rumors of his return to Turkish Politics quite remote.