The Military Option

Dov S. Zakheim
  • Iran’s controversial nuclear program is nearing a crisis point. A combination of factors—progress in enriching uranium, years of defying U.N. resolutions and bellicose rhetoric—has led to growing talk about a military option.
  • Israel continues to be concerned about Iran’s program, given statements by Ayatollah Ali Khamenei and leading Iranian military figures denying the Holocaust and challenging Israel’s existence.
  • The Gulf States, apart from Oman, likewise expressed concern about the program. Saudi Arabia's King Salman threatened to obtain a nuclear capability if Iran develops a weapon. The United Arab Emirates, Turkey and Egypt would likely follow suit.
  • But any military operation against nuclear facilities in Iran, the world’s 18th largest state, would be starkly more difficult and more dangerous than Israel’s air strikes on Iraqi and Syrian nuclear reactors.
  • A single bombing raid, even several raids, is not likely to terminate the Iranian program.
  • The international community is also likely to be deeply divided over a military operation, with opposition from key allies and major powers such as Russia and China.
  • An attack  could be unpopular in a war-weary American society. President Obama has stated that "a military solution will not fix it, even if the U.S. participates.”
Since the mid-1990s, the international community has claimed Iran was engaged in a clandestine uranium enrichment program that could be used to develop a nuclear weapons capability. Calls for more decisive international action increased after revelations in 2002 that Iran had built a secret enrichment facility in Natanz and a heavy water facility at Arak. If sanctions fail to force Iran to abandon the program, Israel particularly has suggested the military option.
But a military strike would be more difficult than the 1981 Israeli attack on Iraq’s Osirak reactor or the 2007 Israeli attack on a Syrian nuclear facility, which was alleged to be a weapons-grade reactor. Iraq and Syria had only one target, while Iran has several targets, some underground and all dispersed throughout its much larger territory.  Iran could have other secret nuclear sites, although Tehran denies it. In mid-2010, Tehran announced plans to build 10 additional sites for enrichment, the first one to begin in March 2011. All were to be built inside mountains. Even Israel admits that a military strike would yield only limited, short-term results. And an American strike, even a series of strikes, might ultimately not be any more successful in putting a permanent halt to the Iranian program.
Iran’s geographic area is one of the world’s largest; it ranks 18th among all nations. Its known nuclear facilities are geographically dispersed:
  • The Natanz facility is 130 miles southeast of Tehran.
  • The Fordow uranium enrichment facility near Qom, identified in September 2009, is southwest of the Iranian capital.
  • The Arak heavy water plant is about 150 miles south of Tehran.
  • The Isfahan nuclear technology research center is in central Iran, 210 miles south of Tehran.
  • The Karaj radioactive storage facility is 100 miles northwest of Tehran.
  • The Bushehr reactor is on the Gulf, more than 500 miles from Tehran.
  • The Parchin weapons development complex, which may also be a nuclear weapons development site, is located 19 miles southeast of Tehran.
Any strike, or series of strikes, may also have to target many other Iranian military facilities to eliminate the danger of retaliatory attacks against U.S. forces in Afghanistan, Iraq, the Gulf or elsewhere in the Middle East. There are hundreds of potential targets, which could include:
  • Medium Range Ballistic Missile sites near Iraq
  • Cruise missile sites
  • 14 airfields with shelters
  • Naval facilities and especially diesel submarines
  • Two chemical plants
  • The major petroleum refinery at Kharg Island could constitute another major target for American forces.
Forces and weapons
To conduct a massive aerial campaign against Iran, the United States could use B-2 bombers launched from Diego Garcia. It could also employ newly operational F-35s, F-22s and F-16s from the territories of one or more of its Gulf allies, carrier-based F-35s and F-18s and the support aircraft that would accompany them: AWACS, electronic warfare aircraft and tankers. The United States could also call on special operating forces to provide targeting and other support.
U.S. forces could employ a variety of weapons to ensure the destruction of underground as well as above-ground facilities. These include BLU 113 bunker buster penetrators and BLU-118 hyperbaric weapons for deep penetration attacks as well as more conventional munitions. In addition, aviation units could be supplemented by Tomahawk land attack missile strikes from Trident submarines based in the Indian Ocean.
Military challenges
One major operational decision confronting both policy makers and military planners will be the actual number and location of potential Iranian targets. If there are secret underground enrichment facilities—and the U.S. intelligence record on Iran has not been consistently stellar—local Iranian dissidents or minorities are unlikely to provide much targeting support. The majority of the population supports the broader nuclear energy program as well as President Hassan Rouhani's efforts to reach an agreement with the world’s six major powers – Britain, China, France, Germany, Russia, and the United States. Iranians therefore could rally around the Rouhani government in the event of a foreign attack, as they did in support of Ayatollah Ruhollah Khomeini after Iraq’s 1980 invasion. 
Targeting would therefore have to rely primarily on two sources:
  • Satellites, which may not have detected underground facilities
  • Special forces, whose best known operation in Iran, the April 1980 Desert One rescue attempt, was an unmitigated failure. How well and freely such forces might operate in Iran 30 years later is a major uncertainty. 
Uncertainty about the location of all facilities would also influence the number of attacks to be launched against Iranian targets. While the United States could easily control the skies over Iran for a single massive attack, it is unclear whether and to what extent such an attack would succeed, given both uncertainty about the location of all potential targets, and difficulty achieving rapid and certain battle damage assessments. Multiple aerial attacks may therefore be necessary.
Depending on the number of targets and sorties involved, an aerial strike could require a very large number of attack aircraft, including several air force fighter/attack wings, three to four aircraft carrier wings, bombers and support aircraft. Aircraft, particularly carrier aviation, may have to be diverted from other missions, notably in East Asia. And if the United States undertakes an ongoing series of strikes, a longer operation would result in a significant redeployment of forces back to the Gulf region.
Neighboring states
Any U.S. operation against Iran involving land-based fighter aircraft would require the cooperation of Iran’s neighbors. Such cooperation cannot be taken for granted, especially for forces deployed in Iraq. The Baghdad government, which is likely to be led by Shiite political parties for the foreseeable future, would almost certainly object to U.S. forces using its territory against its larger and more powerful Shiite neighbor. Article 27 of the 2009 U.S.-Iraq Status of Forces Agreement explicitly prohibits the use of “Iraqi land, water and airspace as a route or launching pad for attacks against other countries.” The costs of violating that agreement—on many fronts—would be high.
The nervous Gulf sheikhdoms would be equally hesitant to do anything more than grant American forces over-flight rights. To permit U.S. aircraft to operate from their soil would amount to an invitation to Iran to destabilize their own regimes. Each country has its own concerns:
  • Bahrain, which is headquarters for the U.S. Fifth Fleet, has a restive Shiite majority that is split between Arabs and Persians.
  • Saudi Arabia has a significant Shiite population in its eastern province, the country’s oil-producing heartland, and would certainly not want to be seen as cooperating with the United States.
  • Qatar, host to the U.S. Combined Air Operations Center, maintains decent relations with Tehran.
  • Oman and Kuwait, which host prepositioned materiel for U.S. forces, also either have dealings with Iran or would want to avoid igniting new tensions in the Gulf.
  • The United Arab Emirates, which continues to contest the shah’s seizure of Abu Musa and the Tunbs islands, might be willing to provide over-flight rights. Even so, Dubai’s tight trading relations with Iran would probably put a brake on just how far the UAE was prepared to go in support of an American strike.
It is even less likely that the United States could conduct aerial strikes from Incirlik or other bases in Turkey. The Turkish parliament denied Washington access to deploy its Fourth Infantry Division against Saddam Hussein in 2003. Nothing more could be expected from the parliament in the event of a proposed attack in Iran. The government of former Prime Minister and now President  Recep Tayyip Erdogan has been outspoken in opposing sanctions on Iran, and would probably oppose any cooperation with U.S. forces on Iran even more vociferously than it did on Iraq in 2003.
The bottom line is that any aerial strike against Iran’s nuclear facilities would have to be conducted primarily by long-range bombers and naval aviation. And it would be difficult especially for the carrier forces to sustain ongoing strikes over a period of time due to the strain on a declining carrier force.
Other options, other targets
The United States could employ Trident-based cruise missiles to attack Iranian nuclear facilities. Doing so would avoid some of the political complications in the region. But cruise missile strikes also tend to be one-off affairs. In addition, they would have uncertain results against underground targets. Finally, it would be difficult to obtain battle damage assessments, particularly about underground targets.
The United States could pressure Iran militarily without actually attacking its nuclear facilities. For example, it could strike the Kharg Island oil refineries, or some other major military or economic targets. These strikes could be carried out by a number of different forces, including carrier-based aircraft, bombers or cruise missiles.
Another option is for the U.S. Navy to impose a blockade on Iranian exports. A blockade or any other use of naval forces operating inside the Gulf would almost certainly provoke an Iranian naval response, possibly swarm attacks by coordinated Iranian Navy and Revolutionary Guard Naval forces. The U.S. Navy could ultimately repel such attacks, using both air and surface forces to destroy the attacking boats. But some Iranian forces may be able to break through the U.S. naval defense and inflict damage. Iran could also circumvent the blockade, at least to some extent, by trading or smuggling goods through Turkey, Central Asia and even Russia.
Finally, the United States could deploy Special Forces, as well as intelligence units, to conduct covert and clandestine operations against elements of the Iranian nuclear program. There have been repeated reports of Israeli attempts to sabotage the program, with some degree of success, which is how the Israelis sabotaged the Egyptian program in the 1960s. These types of operations may not be as dramatic or as immediate as military strikes, but they would lessen the likelihood of retaliation by Iran or its regional allies. At the same time, Special Forces operations also run the risk that Americans could be captured in Iran.
Political repercussions
The United Nations is unlikely to support a military attack. Even the British and the French are unlikely to support anything more than sanctions, while China and Russia have been reluctant to even support serious sanctions.
The biggest danger may be backlash in the Muslim world, especially after prolonged U.S.-led wars in Iraq and Afghanistan. A U.S. strike could certainly stir up sympathy for Iran in the Muslim world, especially among the Shiites in Iraq, Saudi Arabia and Bahrain, and on the Sunni street in the southern Gulf, the Arab Middle East and potentially South Asia. Even quiescent Muslim communities, notably India’s Shiites (who number in the tens of millions), might react strongly against the United States. India has staunchly resisted sanctions against Iran, for geopolitical reasons. Both countries are wary of Pakistan’s anti-Shiite extremists. But Pakistanis of many sects are anti-American and could react violently against U.S. targets in Pakistan. The U.S. Embassy in Islamabad was attacked and burned to the ground in 1979—tied in part to Iran. 
Whether Israel or the United States attacked Iranian nuclear facilities, Tehran would see both as the same. Tehran could retaliate in a variety of ways. It could attack U.S. targets not only in Iraq and Afghanistan, but worldwide. The regime could urge Hezbollah and Hamas to launch rocket strikes against Israel, although whether either would do so is uncertain since Israel has indicated it would in turn retaliate against Lebanon and Gaza in unrestrained fashion. The bottom line is that the possibility of a U.S. or Israeli attack prompting a wider Middle East war cannot be ruled out.
  • An Israeli attack on Iranian nuclear facilities is unlikely to stop the Iranian program for very long. An American aerial strike might be more successful, but it also may not shut down Iran’s program. Only a series of ongoing attacks is likely to accomplish that goal.
  • Yet an overt military operation could make Tehran even more determined to acquire a weapons capability as a deterrent to future attacks.
  • The military consequences and political costs could, over time, mount for whichever nation attacked Iran. Retaliation could play out across the world’s most volatile region and potentially far beyond.
  • Clandestine action against Iranian facilities would be more effective and less risky politically. But a covert effort would also take time, and its success could also not be guaranteed.
Dov S. Zakheim is senior advisor at the Center for Strategic and International Studies and vice chairman of the Center for the National Interest and of the  Foreign Policy Research Institute

This chapter was originally published in 2010, and is updated as of August 2015.