What's Happening in Iran?

A while back the announcer at an Iranian soccer game asked for a moment of silence for the people of Palestine, but the crowd instead erupted into boisterous shouting.

It was a small thing, but I found it telling; many Iranians are so embittered by their own Islamic government that they can't even muster sympathy for fellow Muslims under Israeli bombardment.

This came to mind because Tyler Cowen linked to a tweet about the study from which the chart at the top comes, documenting the steep decline in religion in Iran. Based on survey data, the study found that more Iranians claimed to be atheist, agnostic, or "none" than Shiite. Cowen's comment section then filled up with supporting posts from people who claimed knowledge of Iran and said things like:

1. Islam is seen by younger people as the doctrine of a failed government staffed by a bunch of crooks.
2. And it's a foreign, Arab imposition, while the "real Iran" - the Achaenemids - were Zoroastrians, but quite willing to allow non-judgemental religious pluralism.
3. The IRGC is staffed by redneck losers, or by non-Iranians. (Iran has a separate "regular army" that all Iranian men must join as conscripts.)
4. There is a rather vast city-country divide, with people in the big Iranian cities largely non-religious or dabbling in Zoroastrianism, with the last stronghold of Islam being rural areas, particularly near Afghanistan (and around some of the religious cities).

Or:

Based on my interactions in person and online, most Iranians hate their terrible government and everything it stands for.

And this:

I don't support the US killing Iranians - too many innocents and future friends there.

Which I think is very wise.

But that doesn't answer the question of what is likely to happen in Iran now. The mass protests of the past couple of years showed that hundreds of thousands of Iranians hate the regime and its form of religion, but they were unable to budge it. Does that mean the anti-regime forces are weaker and less numerous than they seem from a western perspective? Or that the regime is willing to hold onto power using force and fanaticism? Experience seems to show that 25% is enough support to keep a dictatorial regime in power, especially when they are the most determined and violent part of the population.

I don't see the Iranian regime falling soon, but I wonder what happens as the people increasinging turn against the mullahs and their ideology.