Two things are clear. The talks have not borne much fruit, so suspending them is almost cost free, at least in the short term. The downside is that the talks have been a way for the two countries, which do not have diplomatic relations, to have face-to-face conversations. Several Iraqi politicians said they believed that the Iranian suspension was as much in retaliation for the United States’ criticism of Iran’s nuclear program as it was for Iraq policy.

“Some Iranian officials believe that Iraq is a better location to pressure the Americans over Iran’s diplomatic crisis with them,” Ali al-Dabbagh, an Iraqi government spokesman, told Al Hurra, a satellite channel, on Monday evening.

In addition, Iran loses nothing in Iraq by denouncing strikes on Shiite civilians, especially since it has also said it approves of the Iraqi government’s effort to halt the activities of illegal militias. While those two positions may sound contradictory, they are plausible here. The Iraqi government also says it wants to help civilians and is taking aim only at the militias. The reality is that when forces go after insurgents in urban areas, it is impossible to avoid hitting some innocents as well.

Fellow Shiites are not the only ones disturbed by the fighting; a delegation from Anbar Province, which is almost entirely Sunni, made the long and dangerous journey to Sadr City on Monday to show solidarity with the poor Shiite community. As American helicopter gunships barraged nearby neighborhoods and people ran inside to take shelter, representatives of influential Sunni tribes, including the Janabi and Hebi, stood shoulder to shoulder with distinguished Shiite tribal leaders in Sadr City.

Ali al-Hebi, 40, said, “The people in Sadr city are like our families, and we are worried about them.”

“We must find a solution for them, and we advise them to not repeat our fault in Falluja,” he added. “The loss of any blood is forbidden, according to our religion as Muslims, and if we do not help them, we will be responsible before history for what will happen here.”

The sheiks’ visit was reminiscent of a similar journey by Shiites in 2004, organized by followers of the radical Shiite cleric Moktada al-Sadr. They gathered food and supplies and brought them to Sunnis in Falluja who were besieged by American forces at the time.