Is Iran getting too old to be such a threat?

Yes, we hear about how young so many countries in and around the Middle East are, but, for Mad Mahmoud Ahmedinejad, Ayatollah Khamenei, et al, the youth boom may not last so long. And, while frustrating to their attempts to tighten their authority, it's had the flip side of "projecting power."

So, why will Iran gray out? How quickly? And, what does it mean?

As far as the why? It's got a rapidly declining birthrate:

As recently as the late 1970s, the average Iranian woman had nearly seven children. Today, for reasons not well understood, she has just 1.74, far below the average 2.1 children needed to sustain a population over time. Accordingly, between 2010 and 2050, the share of Iran's population 60 and older is expected to increase from 7.1 to 28.1 percent. This is well above the share of 60-plus people found in Western Europe today and about the same percentage that is expected for most Northern European countries in 2050. But unlike Western Europe, Iran and many other developing regions experiencing the same hyper-aging -- from Cuba to Croatia, Lebanon to the Wallis and Futuna Islands -- will not necessarily have a chance to get rich before they get old.

This is far more rapid than similar declines in developing nations. That's part of why Iran may not "strike it rich."

Meanwhile, what drives Iran now? What's a good analogy? Despite Ahmadinejad's sometimes buffoonish antisemitism, it's not Nazi Germany. A better analogy might be the old USSR, needing the U.S. as a focal point:

Ayatollah Ahmad Jannati, head of the powerful Guardian Council, put it plainly in a 2009 interview with Etemad newspaper: "If pro-American tendencies come to power in Iran, we have to say goodbye to everything. After all, anti-Americanism is among the main features of our Islamic state."

In fact, KARIM SADJADPOUR says we need just take George Kennan's famous 1947 essay about Stalin's USSR, and replace that with "Iran" and "Communism" with "Islamism."

Combine that with the aging mentioned above, also parallel to the the Soviet Union in a later stage of its life, and one has to ask if Iran of the ayatollahs will implode of its own accord at some point. The most likely answer is no, because it has China as a backstop that Gorbachev didn't.

But, there’s a flip side:

By 2020, the number of 15- to 24-year-old Iranians will have shrunk by 34 percent since 2005, according to the U.N. Population Division. This largely reflects the sharp downturn in the Iranian economy that occurred after its 1979 revolution, as well as the clerical regime's embrace of contraception. But from 2020 to 2035, the number will again swell by 34 percent, even if birth rates continue to decline. Why? A very high proportion of Iranian women are now of childbearing age, which means that even though young Iranian women are having far fewer children than their mothers did -- indeed, not enough to sustain the population over time -- their numbers are still sufficient to create a temporary "echo boom."

So, Iran could become more unstable before any implosion, unstable to the external world.