There is a case to be made that overcoming oppression is extremely hard to achieve in populations over 50 million. Are there any successful examples where this has happened?
The Soviet Union had a population larger than the United States' at the time of its collapse. North of 100 million people were liberated virtually overnight from direct Russian rule, from USSR states (over 50 million in Ukraine alone); and another 100+ million from Russian-backed communist governments in Warsaw Pact states (40 million in Poland alone).
British India (three modern states) had a population of 400 million at the time of its independence from Britain. That was famously a coordinated, nation-wide movement.
Indonesia was around 200 million people at the end of the Suharto dictatorship and its transition towards democracy.
Soviet Union - was that really opposition to oppression that succeeded or the state collapsed internally - disintegrated?
British India could be good example - but there's a case to be made that it was overthrow of an external colonial rule that never integrated with the local population, so not sure there is a good parallel with the Iran situation.
Indonesia - this appears to be a really good example, along with Phillipines (1986). So what's different about Iran - why the repeated failures there?
The Revolutions of 1989 that led to the fall of the iron curtain were bottom up in a region with a large population.
In August of 1989, 2 million people held hands to create a chain. This was one of the large protests in human history. It led to the death of communism in Europe. More information in “The Baltic Way” article below.
I think this is one of the arguments for the 2nd amendment that too often gets overlooked. Overthrowing the government is a lot easier if the populace is legally armed AND the government doesn't know who owns what or how many guns. Which is why it is that way specifically here in the US.
British India (three modern states) had a population of 400 million at the time of its independence from Britain. That was famously a coordinated, nation-wide movement.
Indonesia was around 200 million people at the end of the Suharto dictatorship and its transition towards democracy.