The population of the Middle East may, in terms of sect and ethnicities, be the most diverse in the old world. But there is no rainbow over the region, and there is no rainbow coalition either. What there is is an arc of blood that suffuses the area --sometimes more here, sometimes there--and encompassing denominations, national communities and (among the Palestinians) ideologies. Right now the bloodiest locus is Iraq. But it has for more than two years been showing itself again with ever greater frequency in Lebanon, where blood dominated the news in the the four-part civil war that was a daily occurrence a generation ago. The Times says the bombing of two buses carrying workers to their jobs near the town of Bifkaya, northeast of Beirut, took three lives. (Again with the "at least" modifier.) The AP dispatch in the Jerusalem Post reported that 12 lives were lost. Both reports indicated that many people were injured. No one seems to doubt that, in this case, as in others previously, Murder, Inc. was Hezbollah or Syria itself, perhaps a partnership of the two. After all, Hezbollah and Syria have become a permanent partnership, fueled by Iranian cash and arms expertise. Bikfaya is a Maronite Catholic town and the seat of the Gemayel family whose pater familias founded the "falange" party and militia during the thirties, consciously emulating Franco's political base. Lebanese demography is the key to Lebanese bloodshed. In the seventies, the Palestinians broke the unstable denominational peace in Lebanon. They are now, frankly, despised by all parties. And then there are the Druze, the Shi'a, the Sunnis, the Maronites, and other Christians enclaves. From all of these power groups, there are split-offs. And cross-links. Even among the Maronites.