With its plunge into the Syrian civil war, Hezbollah is taking its followers in an unaccustomed direction, in a gamble that could help rescue it from that threat, bringing it new power and confidence, or end in a defeat with wide repercussions. Hezbollah is betting its prestige and security on the effort to crush a Syrian rebellion that is detested by Hezbollah’s Shiite Muslim base, but popular with the group’s Lebanese rivals and with much of the Sunni majority in the wider Arab world…

Hezbollah’s involvement in Syria, which it long played down, has gradually come out into the open as the casualties mount. In the past month, as the group began helping the Syrian Army sweep villages surrounding the strategic town of Qusayr in an effort to connect Damascus with government strongholds on the coast, 141 fighters have been killed, according to the Syrian Observatory for Human Rights, a Britain-based group that tracks the violence through contacts in Syria. Of those, it said, 79 have died in the past 10 days, a number in accord with counts by researchers tracking Hezbollah Web sites.

To justify the unexpected new sacrifices it is asking from its followers, Hezbollah has framed the risky intervention in Syria as crucial to safeguarding its avowed core missions: challenging Israel, empowering its Shiite community and protecting Lebanon. But if it fails, by Hezbollah’s own assessment the fallout could jeopardize all three of those missions. That would leave the group weakened, with bridges burned at home and abroad, amid growing fears of a regional war between Sunnis and Shiites.