There has been enough evidence in the past few years that suggests Rafsanjani has been trying to create a network of well-connected Iranians in the U.S., with strong ties to neoliberal Americans, especially among the Democrats. This network includes politicians, scholars, and businessmen.

One can speculate that now that Khamanei is convinced it is a good time to establish direct channels between Iran and the United States, he wants to do it through his own trusted group of politicians and diplomats, let's say those close to Ali Larijani. Khamanei knows that Rafsanjani has had extended contacts with the Americans for a long time, and since his trust for Rafsanjani has continually declined in the past decade, he doesn't want him to be involved in the sensitive process of Iran-U.S. relations.

It's a mistake to assume the recent arrests have anything to do with Ahmadinejad or his problems with Rafsanjani, or to think that the Ministry of Intelligence is totally under Ahmadinejad's control.

While I'm not ruling out the possibility of espionage charges against Mousavian substantiated, I think the real motive behind the recent chain of events is that Khamanei wants to dismantle the network that Rafsanjani has created in the U.S. for a day like this.

And to be honest, I personally think businessman-politicians around Rafsanjani are corrupt enough to easily sell out Iran's interests in exchange for personal gains.