[F]aced with the slow-motion collapse of Assad’s regime, senior Iranian officials and clerics appear to be increasingly divided about how to respond. Under an Iranian peace plan unveiled this month, the Syrian president would remain in power through elections in 2014, although he could run again.

“The debate behind the curtains among experts and officials regarding the Syrian crisis is very hot,” said an Iranian journalist with close ties to the office of Iranian President Mahmoud Ahmadinejad, who spoke on condition of anonymity. “Staunch support for Bashar Assad’s regime is costing the Islamic Republic of Iran a lot.”

Shiite Muslim Iran faces increasing isolation if Assad is overthrown by predominantly Sunni Muslim rebels supported by Iran’s regional rivals in the Persian Gulf. Iran would lose a key part of an anti-Israel alliance it has nurtured since the 1980s. And at a time when it faces tough international sanctions because of its nuclear program, Iran risks complicating its problems by being regarded as an obstacle on Syria.

Focusing the blame for the “Syria debacle” could also affect Iran’s next presidential election, scheduled for June.