As President Barack Obama seeks to extricate US troops from Afghanistan - the scene of America's longest war - his administration will soon face another crisis that determines whether US soldiers remain in Iraq. The decision is mostly out of Mr Obama's hands.
Under a security agreement between Washington and Baghdad, the 46,000 US troops still in Iraq are required to leave by December 31. But some Iraqi leaders are pushing for a new agreement that would allow a smaller contingent of US forces to remain beyond the deadline. American commanders argue that Iraqi forces still need help in gathering intelligence and defending the country's borders and airspace.
Prime Minister Nouri Al Maliki has said he will request that US troops remain if a majority of Iraqi lawmakers and political leaders support the idea. But the Iraqi Shiite cleric Muqtada Al Sadr has staked his reputation on forcing US troops out of Iraq.
In late May, Mr Al Sadr's followers staged one of the largest political rallies in Baghdad since the US invasion in 2003. As many as 70,000 supporters gathered in the Sadr City neighbourhood, chanting "No, no, America!" - a message to Iraqi leaders that they should not allow the US to keep troops in the country beyond the end of the year.
The procession was led by thousands of young fighters from the Mahdi Army, Mr Al Sadr's militia which battled US troops for years. Although they were unarmed, the militiamen wore uniforms and marched in disciplined, military formation. This show of force carried another message: Mr Al Sadr is prepared to again unleash his fighters against his Iraqi rivals and US forces if Mr Al Maliki strikes a deal to keep American troops in Iraq.