From the Feb. 12 Washington Post article:

The growing Sunni-Shiite divide is roiling an Arab world as unsettled as at any time in a generation. Fought in speeches, newspaper columns, rumors swirling through cafes and the Internet, and occasional bursts of strife, the conflict is predominantly shaped by politics: a disintegrating Iraq, an ascendant Iran, a sense of Arab powerlessness and a persistent suspicion of American intentions. But the division has begun to seep into the region's social fabric, too. The sectarian fault line has long existed and sometimes ruptured, but never, perhaps, has it been revealed in such a stark, disruptive fashion.

Newspapers are replete with assertions, some little more than incendiary rumors, of Shiite aggressiveness. The Jordanian newspaper Ad-Dustour, aligned with the government, wrote of a conspiracy last month to spread Shiism from India to Egypt. On the conspirators' agenda, it said: assassinating "prominent Sunni figures." The same day, an Algerian newspaper reported that parents were calling on the government to stop Shiite proselytizing in schools. An Egyptian columnist accused Iran of trying to convert Sunnis to Shiism in an attempt to revive the Persian Safavid dynasty, which came to power in the 16th century. ...

The violence remains confined to Iraq and, on a far smaller scale, Lebanon, but to some, the four-year-long entropy of Iraq offers a metaphor for the forces emerging across the region: People there watched the rise of sectarian identity, railed against it, blamed the United States and others for inflaming it, then were often helpless to stop the descent into bloodshed.

"This tension is the most dangerous problem now in the region," said Ghassan Charbel, editor of the Arabic-language daily al-Hayat.