As Hamas confronts Israel, its Arab support swells

The last time Israel launched a major military operation in Gaza, it could count on neighboring Egypt not to pose any significant opposition. Its then-ruler, Hosni Mubarak, was hostile to Hamas, the ideological cousin of the internal Egyptian opposition group the Muslim Brotherhood, and he kept Egypt's border with Gaza mostly shut as Israel waged a war that killed more than 1,000 Palestinians. But in the post-“Arab spring” Middle East, the region looks much different, and Hamas has found a new swell of support as it faces Israel. Mr. Mubarak, ousted in a popular uprising in 2011, has been replaced by an elected president from the Muslim Brotherhood. Instead of a mostly sealed Gaza-Egypt...