Sadr spoke to over 6,000 followers at a in mosque Kufa, and he railed against the U.S. presence in Iraq. "No, no for Satan. No, no for America. No, no for the occupation. No, no for Israel," Sadr chanted at the opening of his sermon. "We demand the withdrawal of the occupation forces, or the creation of a timetable for such a withdrawal... I call upon the Iraqi government not to extend the occupation even for a single day."

Sadr fled Iraq on January 14, after General Petraeus assumed command of Multinational Forces Iraq and announced the Baghdad Security Plan would be taking effect. Sadr immediately left Iraq and sheltered in Iran, and was guarded by Iran's Qods Force, according to reports.

Questions remain on what the impact Sadr's return will have on the ongoing Baghdad Security Plan, the status of the Mahdi Army and efforts to quell the sectarian violence.

It is unclear who returned with Sadr. A large convoy of up to 60 vehicles accompanied him into Iraq. The Mahdi Army fragmented upon Sadr's departure, as senior commanders and paymasters abandoned the rank and file. Abu Deraa, the "Shia Zarqawi" was aid to have fled to Iran in January. Sadr may seek to reestablish command and control over the Mahdi Army, but it remains to be seen if this will be possible. This process will certainly take time.

As the Mahdi Army fragmented last winter, a force of about 3,000 Mahdi fighters were said to have sided with Iran (Sadr has long been considered an Iranian vassal) and are training in Iranian camps. The U.S. and Iraq government courted the more moderate elements of the Mahdi Army in an effort to break the organization apart. The American military was able to enter Sadr city and establish a Joint Security Station with the support of the district's mayor.

Sadr may also be attempting to exploit the current political situation in Iraq. Abdul-Aziz al-Hakim, the leader of the powerful Supreme Islamic Iraqi Council (SIIC), is under observation overseas for cancerous tumors in his lungs. The SIIC recently changed its name from Supreme Council for the Islamic Revolution in Iraq (SCIRI) - dropping the "revolution" from the name in a clear rejection of Iran - and turned away from following Iran's Supreme Leader for religious guidance. With the loss of SIIC/SCIRI, Sadr is now the de facto Iranian proxy in Iraq. The Sadrist political bloc, with its 30 seats in Iraq's parliament, withdrew from the existing government, and lost six ministerial positions.

Coalition forces responded to Sadr's return by killing a senior leader of the Mahdi Army in the southern city of Basra. "Wissam al-Waili, 23, also known as Abu Qader, was shot and killed along with his brother and two aides during the battle Friday afternoon," the Associated Press reported.British troops killed Qader after he resisted arrest. "He was suspected of involvement in planting roadside bombs, weapons trafficking, assassinations and planning and participating in attacks against British troops," Reuters noted. Basra has seen an increase in violence since the British announced they would be drawing down forces in the region.