They are on the rise in Afghanistan, Pakistan, Turkey, Kuwait, Lebanon, Bahrain, Libya, Tunisia, Malaysia, Egypt, and even in London as issues of identity, rights, interests and enfranchisement find sectarian expression.
The deadliness of the attack, and its obvious sectarian intent, prompted unusual expressions of alarm from Iraq's Shiite leadership, which had until now spoken with confidence of Iraq's ability to avoid sectarian strife.
The disdain for truly free expression cuts across sectarian lines.
Egypt also now faces a breakdown in law and order, a crackdown on free expression, an increase in sectarian tensions and a collapsing economy.
Under his rule, the expression of regional and sectarian differences was discouraged and the pattern of political assassination was interrupted, though Croatian nationalists mounted occasional terror campaigns from exile.
That appears to be a lesson that other Muslim societies, where political expression often takes a sectarian course, will have to learn the hard way.Luckily, the extreme example of Iraq remains an exception.
India has long faced an uneasy tension between allowing free expression to its citizens and staunching sectarian violence among its people.
LAYCOCK: We're saying you cannot have sectarian prayer.
"What we thought would provide democratic choices ended up as an expression of demographic preferences" that deepened the sectarian and ethnic divide, Malley added.
It was the third sectarian killing in the province in a week and prompted expressions of fear along with the customary calls for calm.
