The Shiite-Sunni conflict

Shiite-Sunni conflict rises in Pakistan | csmonitor.com - if Shiite conflict with Sunni is international and events in Iraq affect violence in Pakistan - it could point toward an international Islamic war. Or is this a fiction being created by espionage - by stoking ancient wars and conflict between Shiite and Sunni so both Muslim communities act to weaken each other? The best strategy when faced with more than one enemy is to make them fight each other. Let's remember American foreign policy in the 80s was to sell arms to Iran, and Saddam. It seems odd that America does not treat Iran as an ally but instead seems to support the side of "conservative" Arabs, as they are the ones controlling the oil.