Why deadly violence is erupting in Iraq once again

• Muqtada al-Sadr announced he would quit politics, sparking protests targeting Iraq's Green Zone.
• At least 30 people were killed and over 300 injured.
• Al-Sadr told his supporters to withdraw and apologized to the Iraqi people for the violence.

Iraq's Shiite cleric Muqtada al-Sadr announced he would quit politics, and his supporters stormed government buildings in protest.