Yet it also highlights the limited options available to Iran to try to preserve perhaps its most critical alliance in the Middle East, where Tehran has far more rivals than friends. The Iranian initiative proposed Sunday while almost certain to be rejected by Syrian rebel factions marks some of the clearest signals that Tehran's leadership is looking to hedge its bets and remain a player in Syrian affairs if Assad is toppled.
"When it comes to keeping Assad in power, Iran does not have many options," said Meir Javedanfar, an Iranian-born political analyst based in Israel. "As the situation gets worse for Assad, Iran may consider sending more weapons to him and a few senior advisers. However, these are unlikely to be game changers."
Just as the Syrian initiative was announced in Tehran during a gathering that included more than 200 Syrian political and religious figures rebel fighters allied with an Islamist faction announced they had captured an infantry base in the northern Syrian city of Aleppo. It was the second Syrian military site overrun in a week. There are also signs of increasing Western support and aid for the rebel side.
Syria's Vice President Farouk al-Sharaa acknowledged in a newspaper interview published Monday that neither side could "decide the battle militarily" and called for a negotiated settlement to save the country from ruin. It was a rare and candid assessment from a top official that Syria's powerful military appears unable to crush the uprising and suggested the Assad regime may be contemplating an exit strategy as rebel forces move closer to the capital Damascus.
A rebel victory would be a particularly stinging blow to Iran, which has so far been able to leverage some gains in the Arab Spring upheavals such as the fall of pro-Western Hosni Mubarak in Egypt and more Arab pressure on Israel. Iran counts on Syria as a bridge to its proxy Hezbollah a dominant political force in Lebanon and an important foothold for the Revolutionary Guard.
Iran's proposals to end the 21-month civil war appear intentionally vague on the endgame. It supports a transitional government and elections for parliament and president, but does not spell out whether it hopes Assad or at least the core of his regime can hang on. The overall message, though, seems to be that Tehran acknowledges it cannot hang its entire strategy on Assad's survival and needs to build new alliances as contingencies.
One of Iran's likely chief aims is to ensure Hezbollah supply lines remain open even if Assad's regime goes down.
But the main rebel groups are already strongly opposed to Iran and are backed by a roll call of Tehran foes: the U.S. and Western allies, and Arab states led by Saudi Arabia and Qatar. A clampdown on aid routes to Hezbollah could be possible as payback for supporting Assad.
"Iran is concerned about the power of pro-Saudi forces if Assad is brought down," said Tehran-based strategic affairs analyst Hasan Hanizadeh. "It is trying to organize other groups in Syria as alternatives just in case."
It is unclear where Shiite power Iran could find support outside of Assad's Alawite community, an offshoot of Shiite Islam and a minority in Syria fighting a rebellion dominated by the Sunni Muslim sect. Some in the merchant establishment and others loyal to Assad's regime could be a place for Iran to exert possible influence. But there are many wildcards in the mix, including Sunni groups among the rebels that could take a dim view of any Shiite forces.
Any major policy shifts in Iran must be approved by the country's Supreme Leader Ayatollah Ali Khamenei, who last week urged a Syrian cease-fire to allow talks between the opposition and Assad's government.
"One thing is for sure," said analyst Javedanfar. "Despite their friendship, Khamenei will not want to sink with Assad."
Iran also has deeper problems at home.
Western sanctions over Tehran's nuclear program are cutting deeper into critical oil exports, with the U.S. applying greater pressure on Iran's major Asian customers to further trim purchases. Iran's finance minister, Shamseddin Hosseini, was quoted Sunday by the economic daily Donya-e-Eqtesad as saying oil revenue had dropped 50 percent because of sanctions, but said that shifts to non-oil exports and more aggressive tax policies have helped ease the shortfall.
In October as the value of Iran's currency plunged by more than 40 percent in a week some merchants in Tehran's main bazaar chanted against the government's financial aid to Assad's regime.
It's possible that Iran could even boost its money flow to Assad if Russia's support weakens, said Torbjorn Soltvedt, a senior regional analyst at Maplecroft, a Britain-based risk analysis group.
"However, given the extent of Iran's own economic problems as a result of sanctions, its ability to prop up Assad is likely to be limited," he added.
Cautiously, over the months, such reality checks have emerged from Iran as rebel strength and support has grown.
During the summer, several current and former Iranian diplomats published opinion articles questioning whether Tehran should stick by Assad's regime or begin to weigh alternatives. But Iran's top envoy, Foreign Minister Ali Akbar Salehi, appears to reflect the seesaw views from the country's leadership.
Salehi has urged a negotiated resolution in Syria, possibly with a deal for Assad to bow out with elections in 2014. On Saturday, however, he struck a hardline tone by saying Tehran "won't allow" Assad to fall without saying what measures Iran was prepared to take.
A similar two-sided declaration was echoed by Hezbollah leader Sheik Hassan Nasrallah. On Sunday, he urged the Syrian opposition to hold talks rather than fight, but said that predictions of Assad's imminent ouster were mere "wishful thinking" by his opponents in the West, Turkey and Arab world.
"Iran is caught between two political paths," said Salman Shaikh, director of The Brookings Doha Center in Qatar. "It can't simply cut Assad loose, but it can't hang onto him at all costs. It would be foolish to think that Iran is not actively drawing up its post-Assad strategies."
Associated Press writer Nasser Karimi in Tehran, Iran, contributed to this report.