There are two ways the United States can overthrow the government of Iran:
1. Massive military attack
2. Withdraw from Iraq
Inflation in Iran is running at 17%. Lately, Iran is experiencing civil unrest because they don’t have enough refinery capacity to produce gasoline.
If America withdraws from Iraq, it will force Iran to spend massive amounts of money to stabilize and influence their dangerous neighbor. I doubt the Iranian economy is strong enough to handle the burden of Iraq. Before long, either the Iranian government will fall or it will have to be nice to the rest of the world to get help. And that means opening the Iranian nuclear facilities to full inspections and dropping support for Hezbollah.
The current Iranian government is unlikely to make those compromises. That’s why the citizens will demand a new one. Iran isn’t a democracy, but it’s the second closest thing in the region, after Israel. The population of Iran is highly skewed toward young people. That alone spells change. I wouldn’t be surprised if Iran ended up staggering toward a more fully democratic process. The systems for democracy in Iran are already in place. All they need to do is remove the Mullah’s control over which candidates can run.
A violent revolution might be unnecessary. If enough people go to the streets, the Mullah’s in charge could decide it’s in their best interest to be more liberal about allowing who runs for office, and not overruling the politicians after they are elected. The people who get elected might find it in their best interest to get along with the United States and Europe. In a hundred years, I could imagine the Mullahs becoming more like the monarchy in Great Britain, with more moral authority than legal authority.
None of this is likely, because I don’t believe the United States will withdraw enough troops from Iraq to make any geopolitical difference to Iran. It’s just interesting to think about unintended consequences, since those seem to be the only kind of consequences we ever see.