A respected Iran analyst with the Carnegie Endowment for Peace believes the authorities in Iran are prepared to shed blood to suppress the uprising.
Karim Sadjadpour was asked by Foreign Policy's blog Passport whether the opposition would be forced to retreat:
The weight of the world now rests on the shoulders of Mir Hossein Mousavi. I expect that Khamenei's people have privately sent signals to him that they're ready for a bloodbath, they're prepared to use overwhelming force to crush this, and is he willing to lead the people in the streets to slaughter?
Mousavi is not Khomeini, and Khamenei is not the Shah. Meaning, Khomeini would not hesitate to lead his followers to "martyrdom", and the Shah did not have the stomach for mass bloodshed. This time the religious zealots are the ones holding power.
The anger and the rage and sense of injustice people feel will not subside anytime soon, but if Mousavi concedes defeat he will demoralize millions of people. At the moment the demonstrations really have no other leadership. It's become a symbiotic relationship, Mousavi feeds off people's support, and the popular support allows Mousavi the political capital to remain defiant. So Mousavi truly has some agonizing decisions to make.
Rafsanjani's role also remains critical. Can he co-opt disaffected revolutionary elites to undermine Khamenei? As Khamenei said, they've known each other for 52 years, when they were young apostles of Ayatollah Khomeini. I expect that Khamenei's people have told Rafsanjani that if he continues to agitate against Khamenei behind the scenes, he and his family will be either imprisoned or killed, and that the people of Iran are unlikely to weep for the corrupt Rafsanjani family.
The Iranian born analyst added, "I know I shouldn't be saying this as an analyst, but my eyes well when I think of the tremendous bravery and fortitude of the Iranian people. They deserve a much better regime than the one they have"