Their renewed cooperation shows that Hamas and the Iranians have patched up a relationship that deteriorated when they disagreed over support for Syrian dictator Bashar Assad. It also points to how Assad and Iran's wins in Syria strengthens Israel's terrorist enemies.
Iran has long supported Palestinian terrorist groups as well as Hezbollah, a Lebanese terrorist group that controls territory north of Israel. Sinwar's comments bolster concerns that U.S. officials and Congressional observers have had about the conflict in Syria. Although most public discussions about the Syria crisis have focused on the threat of the Islamic State, or Assad's willingness to use chemical weapons against his own people, major world powers have seen a subtler long-term significance to the outcome of the conflict.
Russia and Iran have partnered to support Assad, who had been weakened by the combined threats of U.S.-backed rebels and the radical terrorists who formed the ISIS caliphate. With their help, Assad has recaptured rebel-held territory, while the United States has focused on the defeat of ISIS.
http://www.washingtonexaminer.com/hamas-leader-iran-helping-hamas-prepare-for-war-with-israel/article/2632784