Last weekend’s deadly suicide bombing of a residential compound in Riyadh is the latest in a series of deadly Al Qaeda-linked attacks inside Saudi Arabia that is beginning to resemble a civil insurrection, possibly fuelled by anger over the U.S. invasion of Iraq.Contrary to initial media reports, so far there have been no arrests in the bombing of the Al-Muhaya compound—a brazen attack for which Al Qaeda has taken credit. While two suicide bombers died, the other 13 appear to have gotten away despite a chase through the streets of Riyadh, Saudi sources said today.Even more alarming, U.S. officials say,...