WI: Ayatollah Montazeri succeeds Ayatollah Khomeini in 1989?

I have Grand Ayatollah Montazeri ascend as Khomeini's successor in my timeline, Gorbachev Mk II.

He was willing to have a greater degree of political liberalism, provided it did not compromise the clerical leadership. He would also be more inclined to use soft diplomacy. The Islamic Republic of Montazeri would have been considerably different, especially considering that he would have had a major role writing the constitution if not out of favour.
 
I think a possible POD also is his son not being killed- good article here:

In terms of replacing Montazeri, his son Hojjatoleslam Mohammad Montazeri perhaps could have been most suitable candidate. However he was killed in 1981 by a powerful bomb, planted by the People's Mujahideen movement. Had he stayed alive, it is very possible that Mohammad Montazeri could have become a very powerful politician.

According to Mohsen Rafiqdoost, one of the first senior officers of the Islamic Revolutionary Guards, Mohammad Montazeri was the first person who came up with the idea for this force. He was also one of the first advocates for the creation of a sympathetic force among Lebanon's Shia, which later found fruition in the creation of Hezbollah.
 
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