I get the impression that there is some misunderstanding here. We are telling the Shiites, supported by Iran to not enter Tikrit because in the past these militias have been nasty to folks in Sunni towns. Tikrit was Saddam Hussein’s home town and Sunni. I doubt that this is going to make Iran happy with Obama.
Meanwhile Turkey has expressed considerable annoyance at Iran for messing around in other ME countries like Lebanon, Syria, Iraq, and now Yemen.
http://www.reuters.com/article/2015/03/26/us-yemen-security-turkey-idUSKBN0MM2N820150326
In addition, Saudi Arabia has accused Putin of hypocrisy after reading out loud a letter sent by Putin to the Arab Summit meeting in Egypt. Putin made reference to solving problems in ME without external interference. Given Putin’s extensive influence in Syria, this outraged the Saudi representative.
http://www.reuters.com/article/2015/03/29/us-mideast-arabs-summit-putin-idUSKBN0MP0I920150329
Welcome to Middle East.
Friends on one topic are enemies on others, and shift on a relatively frequent basis.
Everyone has to keep a knife sharpened for everyone else.
As a culture, Arabs tend to be quite emotional. When they fight, it tends to get pretty nasty - far beyond Western rules of war. Nowadays, it is getting worse, with the breakdown of Westernized central governments, and the rise of reliogious,ideological movements.
Kind of a cage match free for all developing.