Iran has been backing armed groups, both Sunnis and Shiites. What’s important for Iran is to let the present volatile situation stay as it is and foment civil war. Iran does not care if Iraq is ruined and it is not important that hundreds and thousands of people lose their lives.
The events in Basra, southern Iraq and other Iraqi cities best attest to this fact. In addition to sabotaging Iraq’s economy, the question is what is Iran’s next hellish solution against the people of Iraq?