Muslims have fought — both figuratively and literally — over the "true" Islam ever since a succession dispute erupted after the death of Mohammed. This divide has followed Muslims to the Western world, where it constitutes a neglected facet of radical Islam in countries struggling to assimilate their new arrivals.

The issue surfaced most clearly when sectarian tensions spread to Europe and America at the peak of the Iraq war. Threats against Shiite mosques were reported in the suburbs of Brussels, while vandals appeared to single out Detroit mosques and businesses owned by Shiites in the wake of Saddam Hussein's execution.

Two recent and rather odd stories build on the trend. Earlier this year, two brothers allegedly were targeted during a Muslim hockey game in Canada because they are not Sunnis. According to their father, Ahmed Buksh, whispers about the boys' affiliation led to chaos:

Both sons were attacked by the opposing players. One son took a stick to the head while another one took a stick to the mouth that broke one of his teeth.

"Before you know it, it was just a massive riot," said Buksh. "I went in there as a father and tried to help."

In addition to the opposing players attacking his sons, Buksh said spectators, some as old as 40, were also involved in the attack that left his boys bruised and battered.

Stranger still is a news item from Australia about warring Sunni and Shiite biker gangs — or, as they apparently say down there, "bikie" gangs. Each group sports the clean-cut "Nike bikie" look and each has participated in escalating violence:

The president of Notorious is a Lebanese-Australian with a long-standing association with a bikie from a colorful Sydney Sunni Lebanese family. …

Notorious is considered by gang squad detectives to be the prime suspect in the Crystal Street bombing. One of its mottos is "Only the dead see the end of war" and its "colors," or coat of arms, is a turbaned skeleton holding twin pistols with "Original Gangster" beneath it. …

On the other side of the conflict is the president of the Comanchero City Crew, a Beirut-born Shiite who grew up in the St. George area.

Islamists attack not only infidels, but also Muslims who adhere to differing views. No doubt more sectarian battles will emerge as Western Muslim populations increase and import ancient rivalries. Less certain is whether governments are prepared to deal with this challenge.