DUBAI, United Arab Emirates - France's riots have set off a round of troubled debate across the Arab world: Most here blame a failure to offer opportunity to immigrants, but others see a more ominous clash of cultures over Islam. Across the Middle East, the images of burning cars and stone-throwing young people have dominated newspapers and television. Analysts have hotly debated the riots' meaning, their cause and whether they might spread. "The anger displayed, and the intensity with which it has spread, is alarming," said one Persian Gulf political analyst, Abdul Khaleq Abdulla. Most attribute the flare-ups to social...