[Reily]

Hamas’ & Hezbollah’s writ is to kill Jews. Iran supplies to best it can arms and money. Hamas’ and Hezbollah’s job is to strike where they think best. Iran does not need to give detailed orders or any orders at all. Foolish to think its hierarchical!

[Alberta's Child]

One of the primary financial backers of Hamas over the years has been Israel. They propped it up and supported it to maintain some level of control among the various factions of Palestinian leadership (PLO, Palestinian Authority, etc.).

And historically, Hamas has been a Sunni Islamic faction, not Shi'ite.