When it comes to Iran, most analysts and commentators speak as if the country were a homogenous monolith comprising Persians. It is not. In fact, the seldom mentioned Achilles heel of Iran is its diverse ethnic and religious make-up. This is highlighted by Brenda Shaffer of Georgetown University, who is a leading expert on Iran's ethnic minorities.

Shaffer projects that Iran's current population of more than eighty-five million is made up of forty-two million Persians, an estimated twenty-seven million Azerbaijanis, and roughly eight million Kurds, five million Arabs, two million Turkmen, and one-and-a-half million Baluch.

So although the Persians dominate and are the largest ethnic group in Iran, nearly half of Iranians define themselves as non-Persians. And these non-Persian groups are not happy campers. Each of them has its own customs, history, culture, and often languages. And as Peter Zeihan notes in The Accidental Superpower, Iran's geography does not help solidify the country. It's a country with mountains and highland valleys.

People in one mountain valley do not necessarily identify with those in the next valley over, much less four over. Keeping all these various groups under the same political authority requires a harsh system to induce cooperation, which is why modern Iran has a million-man army. Iran, in effect, occupies its own territory. The existence of a large army is not an option for Iran.

Ilan Berman writes that it is in Iran's provinces, those areas away from Tehran, where ethnic identity and resistance to the central government are the strongest. Every time the center is weak, the periphery rises. Indeed, this is what is happening now.

With the start of the current round of unrest in Iran in December 20127, Iran's ethnic enclaves emerged as the most vibrant center of resistance to clerical rule. In turn, the Iranian regime reserved some of its harshest repression — including mass arrests and state-sanctioned violence — for cities located in provinces where ethnic minorities dominate. The brutality of the official response reflects how deeply the Iranian authorities fear the political activism and destabilizing potential of the country's ethnic communities. They have good reason to do so; in recent yeasts radical ethnic movements in various provinces throughout the country have emerged as a major domestic security challenge for the regime in Tehran.

As luck would have it, there is civil unrest in the Khuzestan province, which is located at the center of Iran's oil production. This gets the regime's attention.

To get an idea of how fragile Iran might be, Berman writes that average Iranians are so fearful of national fragmentation that they mute their criticisms of Tehran's brutal treatment of the non-Persians in the outer provinces even as they themselves suffer under the regime's lash.

It does not take a geopolitical genius to see that Iran is internally vulnerable. Its enemies could take the county's ethnic divide as an opportunity to sow the seeds of rebellion within Iran. This would be poetic justice. Since the 1970s, Iran has been attempting to export its Shia Islamic revolution to other countries in the region, creating murderous mischief in Syria, Lebanon, Iraq, Israel, and the Gulf countries through its proxies.

To date, these countries have spent their energy and resources responding to Iranian initiatives. This has essentially been a one-way street and a draining exercise for those on the receiving end. A country with resources — say, Israel — could decide that it is time to return the favor and take serious aim at destabilizing Iran. The rationale here is clear. If Iran is tied up with armed civil resistance at home, it will be far less capable of causing trouble far afield. Given the current environment, this might not be that hard to accomplish.