Throughout all the vicissitudes of dealing with Iran, an obvious fact has been insufficiently addressed: The external behavior of Iran's regime is simply more dynamic and more effective than that of any other Muslim regime in the Middle East. Iran has constructed thousands of centrifuges. Tehran has trained and equipped Hezbollah in Lebanon and Shiite forces in Iraq and Yemen, and it has propped up Syria's embattled president. Turkey and the Arab world appear sleepy-eyed in comparison. Iran acts. The other Muslim countries struggle to formulate responses, and when they do, they are still less effective than the Iranians. Why is that so? What secret sauce does the Iranian regime have?

More than merely a state

Iran benefits from being both a civilization and a sub-state. Its Sunni counterparts are merely states, and often creaky ones at that, at a time in history when states are being undermined by other political forces. Indeed, the state model is failing in the Middle East, and Iran's advantage is that its leaders operate at levels both above and below the traditional state.

The modern state of Iran is heir to the imperial civilization of ancient Persia. Its territory broadly aligns with the Mede, Parthian, Achaemenid, Sassanid, Qajar, and Pahlevi states and empires, whose spheres of influence often extended from the Mediterranean to Central Asia. Persia was the ancient world's first superpower, and a bold if sometimes broken line connects the Persian monarchs of antiquity to the ayatollahs of today, whose very aggression is rooted in the geopolitics of their forebears. There are many Arab states, but there is only one Persian state - a state that has historically dominated its immediate Arab neighbours with its ample resources of cultural wealth and political organization. It took nothing less than the suffocating totalitarianism of Saddam Hussein to keep Iran out of Iraq. In the absence of such a dominant influence, Iraq must revert to its default, heavily Persian-influenced normal.

At the same time, Iran's regime bears all the hallmarks of a sub-state - and all the advantages. Like Hezbollah, the various Shiite militias, and al Qaeda, the regime binds a close-knit, determined band of believers that has come to represent an ideology due to the revolutionary clarity of its ideas. Hezbollah, the various other Shiite militias, and al Qaeda have all been effective and innovative because they represent fervent sub-state ideologies. Meanwhile, the Iraqi army and other conventional forces in the Middle East have generally performed less impressively. This is because Arabs, with some exceptions, never really believed in their states, so they never believed in their state armies. Just ask the Israelis, who defeated those armies in the 1956, 1967, and 1973 wars.

The failure to understand this dynamic sits at the root of why the vast and expensive American plan to train the Iraqi army has largely fallen flat. Iran's own state military may also not be very good. But its Revolutionary Guard Corps army and navy are another story: These are lethal and innovative forces because they are outgrowths less of the Iranian state than of the sub-state of radical mullahs. The Revolutionary Guards inculcate an ideology of resistance that also appeals to some Sunnis, whom the Shiite Iranians support in strategic and pragmatic ways. This flexibility on the part of Tehran evinces not only sub-state dynamism, but an ancient imperial mindset, too.

Civilizations represent a thick depository of language, culture, and values. The sub-state represents a dynamic solidarity group. Put the two together, as they are in revolutionary Iran, and you have a formidable adversary to ossifying Arab states.

The Baathist states of the Levant represent a failed secular belief system. The more successful Arab states are family monarchies such as those ruling in Saudi Arabia, the Gulf, Jordan, and Morocco. Yet for the most part even these regimes stand for comparatively little beyond the social peace and security they have been able to provide. They have no exportable revolutionary ideology, in other words, which the Iranian sub-state has in abundance. Saudi Arabia has exported its Wahhabi ideology, but Riyadh has never been able to control its religious supporters beyond its own borders to the degree that the Iranians have.

For example, the Iranians have developed a model for training foreign fighters in Lebanon, Syria, and Iraq of a quality that eludes the programs of most Arab states. In fact, only the U. S. Army Special Forces, or Green Berets, have such a highly developed ability to train foreign fighters worldwide, which they do using a system dubbed Foreign Internal Defense, or FID. Green Berets are part of the Special Operations community because much of what they do, including FID, is so rare. But the Iranians effectively train foreign fighters as a matter of course. It is central to their ability to project military power throughout the Middle East. Also central to their ability to project that power is their quality of being an aggressive sub-state operating within the core of a great world civilization.

The Iranians may yet become overextended in the Levant. It is possible that their success in leveraging Shiite militias against the Islamic State could lead to a broader and deeper Sunni-Shiite war that goes on for years. Iran could then find itself in a quagmire that leads the overwhelming majority of Iranians - who are members of this great world civilization but not members of the sub-state - to turn further against the mullahs. That may be one of the few hopes we have. The problem is not only the inherent cultural strength of the Iranian power structure, but the comparative weakness of its Arab counterparts.