For me, the division arises because Mousavi's letter is actually two statements directed to two different audiences, seeking their recognition and possibly acceptance:
Iran Document: Mousavi’s “5 Stages to Resolution” Statement (1 January)
The Latest from Iran (2 January): The Ripples of the Mousavi Statement
Statement Number 1 is to the activists of the Green movement: "I am with you. I am with you to the end against the injustices and betrayals of this regime."
Statement Number 2 is to the regime: "I do not want to have to go to the end with the opposition. I do not want to do so because this will bring more bloodshed and tear apart the Islamic Republic. So let us move towards an agreement that will restore what is best about our system."
Thus, the first part --- indeed the majority --- of the statement is an eloquent, passionate, at times fiery pronouncement (perhaps significantly, written within a few days of the death of Mousavi's nephew in the Ashura demonstration) that Mousavi stands with the Green movement in its fight. At no point, interestingly, does he claim to lead the movement. Indeed, there is the striking remark that he, as well as Mehdi Karroubi and Mohammad Khatami, refrained from a call for Ashura demonstrations, but still the movement turned out in force last Sunday.
Because Mousavi does not claim to lead the movement, he does not have to deal with the issue of what that movement's demands have moved beyond a "reform" of the Islamic Republic. Instead, he moves to the second part of the statement, a pragmatic, point-by-point description of measures which is cool both in tone and in language --- let us ease the rushing river that both threatens to overwhelm us and stagnates under the burden of conflict.
Those measures are far from new. Indeed, once the conflict moved beyond the question of the results of the Presidential election and to the illegitimate, unjust declarations, threats, and punishment of the Government, they were set out by both Mehdi Karroubi and Mousavi in the autumn. Respect for the Constitution, freeing of political prisoners with compensation for them and their families, acknowledgement of errors, corruptions, and violations by Government officials: these are the steps of restitution and reconciliation within the system.
Well, the tension between the first part and second part seems evident: as an EA reader concisely pointed out this morning, "[The issue is] if these reformist circles still adhere to reforms within the system, or if they have recognized them being impossible in the velayat-e faqih [system of ultimate clerical authority]" of the Islamic Republic."
Put even more bluntly, what happens if Mousavi's 5-point plan is rejected by the Government? The one way out may be the ultimate scapegoating, with the dismissal of President Ahmadinejad both as implicit recognition of the electoral manipulations and explicit condemnation of the corruptions --- political, economic, and ideological; note Mousavi's attention to Iran's economic issues and foriegn policy --- of the Government. Surely, however, that moment passed once the Supreme Leader anointed Ahmadinejad's second term in August.
So what happens when Mousavi is met not by negotiation but by silence or even by more threats? Does he indeed declare that he is with the Green movement to the end --- an end which means not "unity" but more conflict? Does he really declare that not only Ahmadinejad and his inner circle but the Supreme Leader and his have had their last chance?
Does he still stand alongside the factions in the Green movement, not as leader but as "one of them"?