Shia'-Sunni & now Sunni-Sunni battles as 'useful to policy goals'

"... Similarly, Arab leaders (and Washington) often found labeling their rivals as "Shiite" a valuable way to undermine the popular appeal of the Iran-Syria-Hezbollah "Resistance Axis." This isn't to say that some leaders don't genuinely dislike Shiites -- Saudi King Abdullah famously distrusted Iraqi Prime Minister Nuri al-Maliki as an Iranian agent -- but their personal beliefs aren't really necessary to explain their behavior.

For this reason, a "Sunni" conquest of Syria is unlikely to turn the country into a reliable ally of other Sunni regimes in the region unless such alliances happen to serve the self-interest of the new leaders. The traditional rivalry between Qatar and Saudi Arabia has reasserted itself in Syria -- competition between their networks of rebel groups has been one of the major factors hindering the unification of the Syrian opposition. Should a Sunni coalition of some sort take power in Syria, it will likely be the object of similarly fierce battles for influence among ambitious external players.

Remember, we've been here before -- and recently. Today's sectarianism looks very much like that of the mid-2000s, when Iran and Hezbollah seemed ascendant, Vali Nasr warned of the "rise of the Shia," Jordan's King Abdullah fretted about a Shiite Crescent, and the sectarian cast of the execution of Saddam Hussein infuriated even those Sunnis who felt no love for the fallen dictator. Particularly during George W. Bush's administration, Washington appeared to view such sectarianism as useful to policy goals such as containing Iran, undermining Hezbollah, and cementing its alliance of "moderate" Sunni dictatorships...."