IRAQ SAYS THANKS IRAN NOW GO AWAY:

With ISIL no longer a major threat Iraq has surprised Iran (and many others outside the Arab world) by rebuilding relations with Sunni Arab neighbors and telling Iran to back off with any plans it had to dominate Iraqi politics. Senior Shia Arab religious and political leaders have been leaning this way for a long time and Iran thought the war against ISIL was an opportunity to weaken the traditional Shia Arab distrust of Iran. That did not work.
Since 2005, when accurate opinion polls and generally free elections were once again available it became obvious that both in Sunni Arab areas (where there used to be a lot of support for al Qaeda) and Shia areas (where there used to be a lot of support for the kind of religious dictatorship found in Shia Iran) that Iran was seen as the enemy.

A good read.