ABDUL-SATTAR ABDUL-JABAR, 56, is a Sunni cleric who occasionally preaches at the prominent Abu Hanifa mosque in the Sunni-dominated Azamiyah neighborhood of Baghdad. Two of his sons were killed by Shiite militiamen. He blames the United States and Iran for Iraq's strife.
"Right from the beginning, the Americans were trying to create sectarian rifts," he said. "Iran is a country of regional ambitions. It isn't a Shiite country. It's a country with specific schemes and agendas."
Now he fears the strife is returning, and he blames the Shiite-dominated government.
"We feel the government does not consider us part of the Iraqi nation," he said. "There is no magical solution for this. If the Shiites are convinced to change their politicians, that would be a big help."
AHMED SALEH AHMED, 40, a Sunni, runs a construction company in Baghdad mainly employing Shiites. He is married to a Shiite woman. They live in the Azamiyah neighborhood and raise their two daughters and son as Sunnis.
Still, his wife prays with the small clay stone that Shiites — but not Sunnis — set in front of their prayer rugs. She often visits a Shiite shrine in another Baghdad district. Ahmed sometimes helps his wife's family prepare food for Shiite pilgrims during religious ceremonies. But he admits that there sometimes is tension between the families.
"We were able to contain it and solve it in a civilized way," Ahmed said.
Iraqis like to talk politics, he said, and "when things get heated, we tend to change the subject."
When their children ask about sectarian differences, "we do our best to make these ideas as clear as we can for them so they don't get confused," he said. "We try to avoid discussing sectarian issues in front of the children."
Ahmed believes sectarian tensions have been strained because people have abused the democratic ideas emerging from the Arab Spring.
Democracy "needs open-mindedness, forgiveness and an ability to understand the other," he said. "No human being is born believing in democracy. It's like going to school — you have to study first. Democracy should be for people who want to do good things, not for those who are out for revenge."
HUSSEIN AL-RUBAIE, 46, a Shiite, was jailed for two years under Saddam. His Shiite-majority Sadriya district in Baghdad saw considerable bloodshed during the worst of the strife, and he fears it's returning.
"The whole region is in flames and we are all about to be burnt," he said. "We have a lot of people who are ignorant and easily driven by sectarian feelings."
He sees it among his friends, who include Sunnis. "My friends only whisper about sectarian things because they think it is a shame to talk about such matters," al-Rubaie said, "but I am afraid that the day might come when this soft talking would turn to fighting in the street."
Among some of Lebanon's Shiites, it's fashionable to wear a necklace with a medallion in the shape of the fabled double-bladed sword of Ali. It's a mark of community pride at a time when the Shiite group Hezbollah says the sect is endangered by Sunni extremists in the Syrian uprising.
During Lebanon's 1974-2000 civil war, the main fight was between Christians and Muslims. But in the past decade, the most dangerous divide has been between Shiites and Sunnis.
For much of Lebanon's existence, Shiites, who make up about a third of the population, were an impoverished underclass beneath the Christians and Sunnis, each roughly a third also. The Shiite resentment helped the rise of the guerrilla force Hezbollah, on whose might the community won greater power. Now, many Sunnis resent Hezbollah's political domination of the government. The 2005 assassination of Prime Minister Rafik Hariri, a Sunni, increased Sunni anger after Hezbollah members were blamed. Since then, both sides have clashed in the streets.
Syria's civil war has fueled those tensions. Lebanon's Sunnis largely back the mainly Sunni rebellion, while Shiites support President Bashar Assad's regime, which is dominated by his Alawite sect, an offshoot of Shiism. Hezbollah sent fighters to help Assad fight the rebels, enraging Sunnis region-wide.