Reply #45: One possibility.

[Igel]

The one that many of his supporters will endorse.

Might be that he's being magnanimous in his superiority; however, even in defeat that's how you phrase your "offer" of peace, also known as requesting terms, so magnanimity is too ambiguous to be useful a guide.

Might be that he's in danger of having his forces crumble and most of the support for him with them. The other is that he caved when confronted with force. It's one thing to hold out for a week--it's another thing to be able to hold out for a month, actually win a battle, or defeat your enemy overall.

Might also be that he's decided to engage in a bit of jujitsu. He and everybody else has acknowledged that there are elements in his forces he doesn't actually control. This way he gets those forces loyal to stand down; those not loyal have a choice--they fight and possibly lose, or they also stand down. If they stand down, they've shown loyalty and can, presumably, be counted as Sadr's. If they don't, he wins by having unreliable elements purged.

A corollary to the last option is that by having his forces stand down, not only does he show his mastery of his people, but he protects them to fight another day. Perhaps when he has more moral authority behind him and it's not Mr. as-Sadr, but Aytollah as-Sadr.

The received wisdom is that the forces that aren't loyal are loyal to other people in Iran. Sadr's also supported by Iran--seriously so. In having his forces retreat to the sidelines, he'd be also engaging in intra-Iranian manoevring, highlighting the weakness, if not error, of those engaged in supporting the "special units" or whatever the term of art is for the less-than-loyal groups.

There are possibly more ways of thinking about it.