The likelihood that Iran will deploy nuclear weapon systems able to strike targets anywhere in the Middle East stimulates widespread speculation that the United States, with or without Coalition partners, sooner rather than later must take military action to prevent a catastrophe. Enormous penalties unfortunately could follow if U.S. policy makers, planners, and operators fail to understand that Iranian geography is fundamentally different from neighboring Iraq in many respects.
On-site inspections (which are no longer permitted), satellite photos, exiles, signal intercepts, air sample analyses, and esoteric collection efforts confirm the existence of Iranian nuclear programs. Many uncertainties, however, concerning the precise location and status of installations devoted to nuclear weapon research, development, and production will persist, pending much improved intelligence. The following summary, given a shortage of facts, accordingly relies heavily on official speculation.
A nuclear research center in Tehran apparently sets policies, approves procedures, and supports Iranian nuclear programs. Mines near Bandar Abbas and Yazd are indigenous sources of uranium ore. The Ardekan Nuclear Fuel Unit near Yazd reportedly powders and purifies that ore to create "yellow cake." A uranium conversion facility within easy reach of Esfahan allegedly uses yellow cake to produce uranium hexafluoride gas (UF6), which underpins enrichment processes that greatly increase the percentage of U-235, a key ingredient of weapons similar to the bomb that leveled Hiroshima.
Intelligence analysts suspect that the Natanz Uranium Enrichment Facility southeast of Tehran employs centrifuges to produce pellets for fuel rods that power reactors. Weapons of a different type, such as the implosion bomb that incinerated Nagasaki, could pose future threats if reactors at Bushehr and Arak, southwest of Tehran, extract plutonium from spent fuel rods. Several other sites attract suspicion. Whether intelligence collectors have identified the location, purpose, and status of every important installation is questionable.
Region I: Zagros Mountains
A north-south wall separates Iran from Turkey and Iraq, then angles southeast toward Baluchistan. Most of Zone IA, where volcanic cones and deeply-incised gorges are typical, towers at least 10,000 feet. Saline Lake Urmia occupies the only sizable basin. Zone IB, which consists of razor-edged ridges separated by slits best suited for sure-footed goats, parallels the Iraqi border from Kurdistan to the Persian Gulf where it turns east to Bandar Abbas. Few peaks stand out, but many top 13,000 feet. Salt domes, called plugs, trap huge subterranean reservoirs of petroleum in the western foothills near Âbâdân. Zone IC between Bandar Abbas and the Pakistani border features high plains adorned with 6,000- to 7,000-foot desolate hills that skirt the merciless Makran coast where bare rock and sand dunes predominate. (One wonders how Alexander the Great's legions survived without water on their return from India to Babylon in 325 B.C.).
Region II: Northern Highlands
Steep-sided, deep-gullied Elburz Mountains, which form an arc between Azerbaijan and southwestern Turkmenistan, rise abruptly above the Caspian Sea from below sea level to an average elevation twice that of the mile-high city, Denver, Colorado. Near Tehran towers the 18,600-foot, permanently snow-capped Mount Damavand, the loftiest point in Europe and Asia west of the Hindu Kush. Ranges half as high as the Elburz parallel Iran"s northeastern frontier from the Caspian Sea into Afghanistan. Alpine forests cover north-facing slopes of the Elburz, but Region II otherwise is barren, except for riverine lowlands around Mashhad.
Region III: Eastern Uplands
Jagged peaks, rockslides, and drifting sand straddle Iran's inhospitable eastern border. Braided streams change course without warning. The Helmand River, which terminates in a shallow lake where Iran, Afghanistan, and Pakistan abut, inundates hundreds of square miles whenever runoff from heavy rains in adjacent hills flood contiguous plains.
Region IV: Central Plateau
Half of Iran occupies a parched plateau. The Dasht-e Kavir or Great Salt Desert, a wasteland 500-miles long and 200-miles wide north of Yazd, is pocked with dry lakebeds that possess sharp-edged salt crusts above sticky black mud much like quicksand. Few of those sumps are solid enough to support men or beasts of burden, much less vehicles or aircraft. The blistering, lifeless Lut Desert trends north-south for 200 miles between Kerman and Region III. Jagged ridges that separate wind-swept corridors dominate the western half. The eastern half features sand dunes as tall as the Washington Monument. Few lonely tracks cross those godforsaken territories. Widely separated cities like Qom, Esfahan, and Shiraz consequently occupy less repellent fringes.
Iran, which is one-fifth as large as the continental United States and is more than twice the area of Iraq, measures 1,220 miles from Tabriz to Châbahâr and 770 miles from Âbâdân to Mashhad (Map, page 53). Four distinctive regions are identifiable. (See below.) Mountains essentially surround a high plateau, much of which is inhospitable.
- Climate. Precipitation is plentiful in the western Zagros and Elburz mountains, but capricious and sparse elsewhere. Two eastern provinces, for example, recently registered rainfall 87% and 72% below average. Cloud cover seldom exceeds 4/10 in most places. Narrow coastal strips between Âbâdân and Châbahâr simulate a subtropical regime, whereas winters in the remainder of Iran are much harsher than in neighboring Iraq. The Lut Desert, in sharp contrast, probably experiences the world's hottest summers. Violent winds that sandblast transients in the worst of Region IV often accompany temperatures that are much higher or lower than maximum and minimum averages. Downpours may deposit a month"s (even a year's) worth of rain in one day.
- Lines of Communication. East-west lines of communication, such as the Silk Road, transited Iran in the distant past but decayed several centuries ago. Rehabilitation since the 1930s has produced a "T" that links Mashhad with Tehran and Tabriz, then heads south to the Persian Gulf. The country has approximately 50,000 miles of paved roads, of which fewer than 300 miles conceivably could be called expressways. Standard-gauge rail lines total fewer than 4,500 miles. Hard-to-negotiate offshoots through the Zagros Mountains, all engineering marvels, fell into disrepair during the Iran-Iraq War of 1980-88. Iranian rivers are useless for military purposes; only one is navigable and that only for shallow-draft boats. Three international airports are noteworthy: Tehran, Âbâdân, and Esfahan. About 40 others have paved runways that equal or exceed 10,000 feet. Capacities of seaports on the Persian Gulf and Makran coast are skimpy by modern standards.
- Population. Iran, like Iraq, is predominantly urban, but the population-68 million compared to 26 million-is 2.5 times as great. Five Iranian cities house more than one million inhabitants. Tehran, at 11 million, is the second most populous city in the Middle East after Cairo. Esfahan at 2.6 million; Mashhad, 2 million; Tabriz, 1.2 million; and Shiraz, 1.2 million lag far behind, but are growing fast. So are Ahvaz, Qom, Kermanshah, and Zahedan, each of which tops 500,000. Small towns, villages, and hamlets nevertheless litter the landscape. Nomads predominate in desolate areas despite concerted efforts by hard-nosed Reza Khan Pahlavi, the then-shah, beginning in the 1930s.
Geographic regions influence military plans and operations at every organizational level. The following analysis views strategic, tactical, and logistic implications within Iran from the standpoint of senior commanders.
- Key Terrain. Physical features, natural and artificial, constitute the environmental foundation for military objectives and targeting policies. Those that promise distinctive (sometimes decisive) advantages if seized, retained, destroyed, or indirectly controlled qualify as key terrain. Baghdad clearly was the strategic center of gravity during early stages of Operation Iraqi Freedom (OIF), whereas several widely-scattered sites would be similarly significant if President George W. Bush authorizes military strikes to terminate Iranian nuclear weapon programs. Top-level U.S. planners, unlike their predecessors in Iraq, thus would have to identify truly key terrain and set priorities before such strikes could sensibly proceed.
- Avenues and Obstacles. High-speed avenues led from Persian Gulf ports to Baghdad when OIF kicked off in March 2003, but parallel advantages would be unobtainable in Iran, where distance and topographical obstructions deny easy overland access to all potential objectives, save the nuclear reactor at Bushehr. The Zagros Mountains impose daunting obstacles to road and rail traffic between Iraq and Iran, because bottlenecks are commonplace. Needle-eye passes, which are few and far between, are easily blocked at both ends. That is why then-Lieutenant General P. X. Kelley and his successor, Lieutenant General Bob Kingston, were reasonably relaxed in the early 1980s when told the objective of their Rapid Deployment Joint Task Force was to keep Soviet tanks from pouring through to Persian Gulf petroleum facilities.
Parachutists and airmobile troops could leapfrog into Iran, but other ground forces would have to breach the mountain barrier, then travel several hundred miles to most target areas. Tanks and other armored vehicles that tend to break down on long trips accordingly would avoid wear and tear only if heavy equipment transporters carried them until contact with enemy forces seemed imminent. Salt pans and shifting sand would make cross-country travel wretched for wheels as well as tracks in Region IV, which apparently contains many of Iran's most important nuclear installations.
No geographic impediments restrict the employment of air power, which could easily eradicate Iranian underground nuclear installations as well as sites on the surface, because none is deeply buried in bedrock as are those in North Korea. Success, however, would demand precise coordinates, and direct hits on an active nuclear reactor could expose thousands of civilians to radioactive fallout. The U.S. Navy could prevent rogue suppliers from funneling nuclear raw materials and finished products through Iran's Persian Gulf and Makran coast ports, but cargo aircraft laden with illicit supplies could land unimpeded, and U.S. experience with illegal Mexican immigrants suggests that concerted efforts to seal overland routes through Turkmenistan, Afghanistan, and Pakistan would fail.
- Observation, Cover, and Concealment. Sere, flat landscape similar to Iraq's desert would afford fine fields of fire for flat-trajectory weapons east of the Zagros Mountains and south of the Elburz. Dry stream beds, isolated dunes, and folds in the ground would offer minimal cover throughout Region IV, where vehicular columns would raise tell-tale clouds of dust that would mark movements off the few paved roads. Formations at rest would also be visible, because aerial observers claim clear views as far as naked eyes and sensors can see. U.S. armed forces, which could quickly establish air superiority, thus would enjoy priceless advantages if Iranian troops counterattacked.
Dust storms nevertheless could cause disastrous complications, as would-be U.S. hostage rescuers discovered during Operation Eagle Claw in 1980, when everything went wrong en route to and at Desert One, a hand-picked staging site in the Dasht-e Kavir. U.S. Air Force Special Tactics chief Colonel John T. Carney Jr., for example, surveyed a hard-packed surface on the night of 31 March-1 April, but fixed-wing aircraft and helicopters landed ankle deep in powdery sand three weeks later. Towering dust clouds discouraged two chopper pilots, who returned to the aircraft carrier USS Nimitz (CVN-68) before reaching Desert One. Another, blinded by dust, collided with a C-130 transport on site. Eight men died, and the mission aborted.
- Logistical Hurdles. Challenges to supply and maintain U.S. armed forces on Iran's central plateau would be far more complex than those that confront logisticians on Iraqi flatlands, where they benefit from easy access to Persian Gulf ports. Aerial deliveries could sustain relatively small contingents as they have done in isolated Afghanistan since October 2001, but division-size formations would demand truck convoys. The transport of large daily loads over land between coastal points of debarkation and the interior would have to inch through mountain passes barely wide enough for one-way traffic during fair weather.
Personnel and equipment performance after arrival in Iranian deserts would duplicate debilitating conditions in Iraq. Abrasive, windblown sand and silt would clog machines, jam weapons, seep past engine filters, pit radarscopes, and otherwise magnify maintenance requirements. The service life of equipment would fall short of normal predictions, despite preventive measures. The absence of sizable rivers, moreover, leaves most of Iran bone dry. Logisticians consequently would have to import immense quantities of water to satisfy human needs and keep engines cool.
It has been said that military practitioners and their civilian supervisors who purposefully make geography work for rather than against them are winners more often than not, whereas those who lack sound appreciation for physical and cultural factors succeed mainly by accident. The current crop of top-level U.S. leaders would be well advised to heed that message before they decide that military power is the most suitable instrument with which to terminate Iran's nuclear weapon programs.
Colonel Collins is the author of Military Geography: For Professionals and the Public (National Defense University Press, 1998). His "Military Geography of Iraq" was a Proceedings Web Exclusive in 2003  .