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For the last decade, the international community has taken a variety of diplomatic and coercive measures to persuade the Iranians to give up their nuclear weapons program and to avert the need to use military force to slow down or destroy the project. To date, these sanctions and negotiations have failed and Iran has made steady progress toward reaching the capability to build a nuclear weapon. The latest estimates are that Iran should have the means to build a bomb by the spring of 2013.

- Introduction
- Iranian Capabilities
- Iranian Threats
- War Options
- Israeli Attack
- Large Cost for Short-Term Benefit?
- America's Reaction
- A U.S. Attack
- Multilateral Actions
- Cyber War


Israeli officials have repeatedly said that Iran poses an existential threat to Israel and that it will not allow Iran to build a bomb. They have hoped that this implied threat would motivate the international community to act. The fear of Israel taking unilateral action no doubt played a role in the imposition of increasingly tough sanctions and more urgent negotiations. The only country, however, that has called for an attack is Saudi Arabia, which believes it has the most at risk if Iran has the bomb. The Saudis have been frustrated by the failure of both the Bush and Obama administrations to act and publicly said they would acquire a bomb if Iran was allowed to develop one.

Based on the IAEA reports and other intelligence, the time is rapidly approaching when more dramatic steps will be necessary to stop Iran if Tehran continues to ignore the will of the UN. In what is viewed as a last resort, a military strike may be the only way to halt Iran's nuclear progress.

Israel does not want to go to war with Iran if it can be avoided. Given Iran's threat to the Arab world as well as U.S. and European interests, Israel believes one or more other countries should take action against Iran to protect those vital interests. Israel and the United States disagree, however, on the point at which it will be too late to act. Israel believes that Iran must be stopped before it reaches the "zone of immunity," when it will have the capability to assemble a bomb, whereas the United States has suggested it could still act even after Iran built a bomb.

The United States and Israel also disagree on the implications of taking military action. The U.S. and others believe the cost of any attack is likely to exceed the benefit of what many believe will be only a short-term delay in Iran's ability to build a bomb. Prime Minister Benjamin Netanyahu has argued this argument is backward - he believes the cost of not stopping Iran would be higher than the expense of taking action. As he said in 2012, "There's been plenty of talk recently about the costs of stopping Iran. I think it's time we started talking about the costs of not stopping Iran." A nuclear-armed Iran, he said:

  • Would dramatically increase terrorism by giving terrorists a nuclear umbrella; that is, Iran's terror proxies such as Hezbollah and Hamas will be emboldened to attack the United States, Israel, and other countries because they will be backed by a power that has atomic weapons.
  • A nuclear-armed Iran could choke off the world's oil supply and make real its threat to close the Straits of Hormouz.
  • If Iran gets nuclear weapons, it would set off a mad dash by Saudi Arabia, Turkey, and others to acquire nuclear weapons of their own.  The world's most volatile region would become a nuclear tinderbox waiting to go off.
  • And here's the worst nightmare of all, with nuclear weapons, Iran could threaten all of us with nuclear terrorism.

Still, Netanyahu said, Israel prefers a peaceful resolution to the issue (AIPAC Policy Conference, March 5, 2012).

Besides the basic desire to avoid war, a number of factors mitigate against a military operation. The Europeans are unlikely to act without the United States because they lack the military capability to sufficiently damage the Iranian facilities and, more important, lack the will to use force. It is possible that one (most likely Britain) or more may be willing to act in concert with the United States.

The United States is the one country that has the military capability to destroy or at least seriously set back Iran's nuclear program. Nevertheless, the United States has its own reasons to hesitate besides the potential consequences of initiating a war. First, before resorting to military force, the president wants to demonstrate to the American people that he has done everything possible to avoid war. Second, the Obama Administration wants to focus on the economy and domestic issues and, to the extent it has any interest in foreign policy, it is to become more engaged in Asia. Third, Obama does not want the United States to fight a third war with a Muslim country after pledging in his first foreign policy address in Cairo in 2009 that one of his goals was to improve ties with the Muslim world. Fourth, after bringing troops home from Iraq and planning to withdraw those in Afghanistan, he is reticent to risk putting troops in a new theater of conflict. Fifth, Obama eschews unilateral moves and may be reluctant to act without a multilateral consensus that there is no other option and without at least one other major power joining any military operation.

Iranian Capabilities

Iran was reportedly using reinforced materials and tunneling deep underground to store nuclear components in an effort to protect them in the event of an attack (AP, March 4, 2005). Public reports suggest Iranian facilities are now so deep underground only the largest "bunker buster" type bombs could damage them and the United States is the only country that has these weapons.

Iran also built a network of tunnels and upgraded its air defenses to protect its nuclear facilities from possible attacks (Telegraph, January 25, 2006).

Iran has also upgraded its offshore capabilities. In November 2012, the Iranian Navy unveiled two new submarines and two missile-launching warships. Earlier, Iranian officials had said they planned to design nuclear-powered submarines, which could enable the navy to keep the subs on patrol for longer periods and distances.

This new capability is viewed as a potential threat to the strategic balance in the Persian Gulf and, therefore, to the United States and the West (DPA, November 28, 2012).

Iran also can order its proxies in Lebanon, Hezbollah, and allies in Gaza, Hamas, to fire rockets at Israel from the north and south to punish Israel. The threat of doing so is also meant to deter Israel. Israel, however, has already made clear that any attacks from Lebanon would be met with a severe response and the Lebanese government is not anxious to be dragged into another war by Hezbollah. Similarly, Hamas may be reluctant to provoke Israel to mount a largescale operation in Gaza that would further weaken its position.

In September 2013, Iran and Oman signed a defense cooperation accord, but that is not likely to have an impact on Iran's ability to attack or defend itself (Jomhuri Islami, September 20, 2013).

Iranian Threats

Iran has repeatedly made bellicose threats regarding the consequences of any attack, especially one initiated by Israel. For example, Masud Yazaiari, spokesperson of the Iranian Revolutionary Guards, said an Israeli attack would not succeed. "They are aware that Tehran's response would be overwhelming and would wipe Israel off the face of the earth" (Maariv, July 27, 2004). In April 2007, Mohammad Baqer Zolghadr, Iran's deputy interior minister in security affairs, said Iran will strike U.S. interests around the world and Israel if attacked. "Nowhere would be safe for America with [Iran's] long-range missiles ... we can fire tens of thousands of missiles every day," Zolghadr said (Haaretz, April 26, 2007).

War Options

Most discussions of the military option have focused on worst-case scenarios - Iran's program can only be delayed, not stopped; a wave of terror will be unleashed by Tehran; Iranian allies, Hamas and Hezbollah, will rain missiles down on Israel; the Muslim world will be inflamed; the price of oil will skyrocket and damage the world economy and other potential catastrophes discussed here.

One other concern is collateral damage. The potential for civilian casualities, property damage or radiation exposure is an important consideration in military planning. One reason why a military option may be pursued sooner than later is that the danger of the release of radiation will be small or non-existent if an attack is launched before nuclear fuel is loaded into any reactors. According to one 2013 study, the most likely targets of any attack are facilities that are built underground or store their hazardous materials in underground bunkers, which would reduce the expected risk to the environment and population (, August 14, 2013).

Any military planner must take into account such worst-case scenarios, but if all decisions were based on these predictions, no wars would ever be fought. Strategists must also consider best-case scenarios as well as those in between the optimistic and the apocalyptic. Here we examine some of the steps already taken to stop Iran and some of the publicly discussed military options.

An Israeli Attack

A number of analysts have questioned Israel's ability to conduct a military operation; however, Israel's chief of staff, Lieutenant General Benny Gantz, said the country's military was capable of attacking Iran on its own without foreign support. If necessary, he said Israel could fight alone without the help of the United States or other countries. "We have our plans and forecasts ... If the time comes we'll decide" on whether to take military action, he said. This echoed earlier comments by Prime Minister Netanyahu who reiterated that Israel would not "abandon our fate into the hands of other countries, even our best friends."

Gants said no attack was imminent and that Israel is willing to give sanctions a chance, but he warned that without greater "sanctions, isolation and continued pressure," Iran could achieve a "nuclear capability before the end of the year" (AFP, April 16, 2013).

A number of options are available for potentially attacking Iran. Some of those suggested in the media have included facilities assassinating the country's leaders or nuclear scientists; bombing the entrances to prevent scientists and others from reaching them; destroying Iran's main oil terminals and crippling the economy; and bombing the enrichment sites. Press reports have also disclosed covert operations to disrupt the nuclear program. For example, Israel reportedly "used front companies to infiltrate the Iranian purchasing network ... to deliver faulty or defective items that ‘poison' the country's atomic activities" (Telegraph, February 16, 2009). The world also learned of joint U.S.-Israeli efforts to sabotage Iranian centrifuges through the use of computer viruses such as Stuxnet.

Many analysts argue that Israel lacks the military capability to stop the Iranian nuclear program for more than a few years. This is the conventional wisdom, but it is just that, conventional, and Israel has repeatedly proved that it has the daring and creativity to disprove the skeptics.

Consider Israel's history. American officials have been consistently wrong about Israel's capabilities. They did not expect Israel to survive the Arab invasion of 1948. In the early 1950s, the Arabs were seen as strategic allies, but, by the end of the decade, Israel was acknowledged as the only pro-Western power in the region. In 1967, no one anticipated that Israel would surprise their neighbors and destroy their air forces on the ground. In 1976, Israel shocked the world when it rescued 102 hostages in Entebbe. In 1981, Israel flew through Arab air space and destroyed Iraq's nuclear reactor. In 2007, an Israeli raid destroyed a suspected Syrian nuclear facility.

Now Israel's capabilities are again being doubted. Only a handful of Israelis are privy to plans that could be far more audacious and innovative than critics imagine. As Eitan Ben-Eliyahu, who flew a fighter escort on the raid on Iraq told the Jerusalem Report, "you can introduce dozens of improvisations and creative ideas and get much more out of the basic conditions than would seem possible at face value."

The most commonly assumed Israeli option would involve an aerial bombardment of Iranian nuclear facilities. The problem analysts frequently mention with regard to Israel bombing Iran is that the Iranian facilities are hidden deep underground. The Obama Administration has sold Israel bunker buster bombs; however, only a handful of Israeli planes can carry them and the munitions are not believed to be powerful enough to penetrate deep enough to destroy the plants.

In addition to aircraft dropping bombs, Israel could also launch its Jericho missiles and possible submarine-based cruise missiles.  This last possibility, a submarine-based attack, became more realistic following reports that Israel launched an attack with precision guided missiles that destroyed a shipment of Russian missiles anti-ship missiles in the Syrian port of Latakia (Tom Gross, “Was Israel's Latest 'Air' Attack on Syria from a Submarine?” Weekly Standard, July 20, 2013). Gross also raised the possibility that Israel could use another tactic -- an EMP (electromagnetic pulses) that could “be emitted from installations the size of a suitcase smuggled into Iran by land and used to disable specific buildings or target specific offices – for example, the office of the Iranian defense minister, to make it impossible for him to communicate by phone or computer with the outside world for a period of time.”

Unlike the United States, which could carry out sustained strikes, Israel is expected to have only a brief window - perhaps only a single raid - to do whatever damage it can. The likely targets would be the heavy-water production plant at Arak, the uranium-conversion facility at Isfahan, and the uranium enrichment centers at Natanz and Fordow. The length of an attack may be constrained, but it could still be potentially devastating if Israel uses its full range of resources, including strikes from the air, land and sea, EMPs and cyberattacks and special forces operations.

One other scenario is referred to as the "Entebbe Option." The idea would be for Israeli commandos to storm the enrichment facility housing Iran's centrifuges, remove the enriched uranium and then destroy the facility (Foreign Policy, September 27, 2012).

According to reports in mid-2013, the Arak facility has become a growing concern as analysts predict Iran may be capable of producing a plutonium-based bomb sometime in 2014. Prime Minister Benjamin Netanyahu said on July 14 that Iran was not yet able to build such a bomb, “but they're getting closer to it. And they have to be stopped.” The heavy water reactor is considered more vulnerable to attack than the enrichment plants and Israel may be forced to act before nuclear materials are introduced into the facility because of the possibility of nuclear fallout from an attack (Washington Post, August 5, 2013). A similar concern prompted Menachem Begin to destroy the Iraqi reactor at Osirak in 1981.

Large Cost for a Short-term Benefit?

Assuming Israel can launch an effective strike, what about the argument that it will only set Iran back a few years?

Maybe the strike will succeed in destroying more of the program than the naysayers believe. But assume that it does not. This does not mean the Iranians can rebuild the program quickly, if at all. They will still have the technical knowledge, but it took them about 20 years to get to where they are today. They will also face much greater international scrutiny. The world kept its head in the sand for years, and the IAEA failed to detect the illicit activities, but that will not happen in the future. Furthermore, sanctions can remain in place, inspections could become more rigorous and other measures taken to ensure the nuclear program is not rebuilt.

Some argue the Iranians will become more united as a result of their nation being attacked. They may also become more determined to get a bomb to ensure that no one can attack them in the future and become even more secretive. This is indeed one scenario, but others are also conceivable. Given the dramatic changes in the Middle East in the last year, isn't it possible that an upheaval will occur in Iran as well and that new leaders will abandon the nuclear option? The Iranian people may conclude that their fanatical leaders brought a catastrophe upon them and that it is time to revolt and to restore Iran to the community of nations. Senior leaders may die in the attack, which might facilitate regime change.

Public discussions of the military option have all assumed that Iran will respond to any attack as their leaders have threatened. Other scenarios are also possible. Israel attacked both Iraqi and Syrian facilities and neither country counterattacked Israel. The Iranians know that if they strike back, Israel can respond in devastating fashion. Israel would overwhelm Lebanon and Gaza if Hezbollah and Hamas entered the fray. An Iranian attack on American targets or interference with oil supplies would provoke an overwhelming U.S. response and might bring other Western powers into the fight.

America's Reaction

One unanswered question is what the United States would do in the event of an Israeli military operation. U.S. officials hope and expect that Israel will inform them in advance, but Israel may choose not to do so. One reason for keeping the U.S. in the dark is to avoid the possibility of President Obama opposing the decision taking measures to stop it. If Israel ignored U.S. wishes, it would risk alienating the president and possibly losing political, military and/or economic support in the aftermath of the Israeli strike. Given U.S. assets in the area, it may be difficult if not impossible to surprise the United States and it is more likely Israel will, as it has in some previous instances, alert the president after the operation has begun.

The United States should not be surprised if Israel acts given the repeated statements by Prime Minister Netanyahu and other officials that Israel will not allow Iran to build a nuclear weapon and will act if others do not. In 1981, Israel sent similar messages to the Carter and Reagan administrations, but, much like today, American assessments of Iraq's nuclear program were different than Israel's and the Israeli warnings were not heeded.

American officials have said they do not want to appear complicit in an Israeli attack, but the Iranians and the Arab/Muslim world will assume that Israel is acting with U.S. help and/or permission and may have a negative reaction. The United States will therefore have an interest in seeing that Israel's operation is as short as possible and preventing the situation from escalating. To do this, however, the United States may be forced to take a more active role in defending Israel, particularly against missile attacks from Iran, Hamas or Hezbollah. This may necessitate the deployment of Patriot missile batteries or threatening military intervention.

President Obama has already taken steps to minimize one of the principal concerns of the United States and its allies, namely, an Iranian threat to the supply of oil. Defense Secretary Leon Panetta suggested that a military attack on Iran would ruin the world economy because of its impact on oil prices (Fox News, November 18, 2011). At a minimum, an Israeli strike is likely to cause a spike in oil prices because of fears of what Iran might do and the tendency of prices to rise whenever there is instability in the region.

If Iran were to carry out its threats to attack ships in the Persian Gulf, place mines in the water or otherwise interfere with the shipment of petroleum, oil prices would rise even higher given that roughly 20 percent of the world's oil passes through the Strait of Hormuz. President Obama has made clear through words and deeds, including the movement of substantial naval assets to the Gulf, that any Iranian threat to oil supplies would cross an American red line that would trigger a military response.

A U.S. Attack

Israel has said that if Iran achieves the capability to build a nuclear weapon, it will have crossed a red line requiring a response. The United States, however, has refused to discuss a "red line" and maintained that Iran would have to reach a higher threshold; that is, the actual production of a nuclear device, before it would consider going beyond the steps it has already taken to discourage Iran from pursuing a weapon.

Since first taking office in 2009, Obama has hoped to achieve a diplomatic solution. He greeted the Iranian people on the Persian New Year, offered unconditional negotiations and offered to let Iran pursue peaceful nuclear energy. Iran's leaders rejected all the President's offers. Meanwhile, U.S. intelligence was learning about a secret enrichment facility and an acceleration of Iran's nuclear program. The Israelis were also becoming increasingly concerned and becoming more outspoken about the need for a military strike, a move Obama opposed and wanted to avoid. Obama convinced the Israelis to hold their fire and both sides apparently increased their covert activities, notably cyberattacks reportedly carried out jointly. Iranian nuclear scientists were also targeted and at least four assassinated. No evidence was ever produced to identify the assailants, but the widespread assumption is that Israel was involved.

Within the Obama administration, a debate was raging between his advisers who believed Iran could be contained and those who favored U.S. intervention as a last resort. Obama was reportedly convinced by the argument that "a nuclear Iran would spell the end of the international regime limiting the spread of nuclear weapons" and undermine his efforts to strengthen the Nuclear Non-Proliferation Treaty and negotiate a new nuclear arms reduction deal with Russia (Time, March 11, 2013).

The Defense Department has also been more actively preparing for a possible military engagement with Iran. The United States moved troops as well as naval and air assets into the Persian Gulf region, whicht represent the largest buildup of American forces since the 2003 Gulf War. Equipment has been prepositioned and a special forces operations base established on a converted transport ship. A previously secret drone base in Saudi Arabia was revealed in the media. Obama also ordered the transfer of defensive systems such as X-band missile-defense radars to Israel, Turkey and Qatar (Time, March 11, 2013).

Should the United States decide to use military force against Iran, it has a range of options. One would be to bomb the nuclear facilities. The U.S. has the capability of carrying on a sustained attack over an extended period. It also has newly developed bunker busting bombs that are much more powerful than those given to Israel. The GBU-57 or Massive Ordnance Penetrator, can penetrate through 200 feet of hardened concrete before detonating.

The United States is also likely to strike far more targets than Israel. The Israelis will be concerned primarily with the nuclear facilities, but an American strike would probably aim to take out missile bases, launchers and production facilities as well. A U.S. operation might also target Kharg Island, the source of most of Iran's oil exports, as well as refineries, natural gas terminals, railways, bridges, roads and power plants. A no-fly zone and/or naval embargo could also be imposed, which would cripple the regime and damage the economy.

Gen. James Mattis, head of U.S. Central Command, said the U.S. military has the ability to bring Iran to its knees. "There are number of means to do that," he said, "perhaps even short of open conflict. But certainly that's one of the options that I have to have prepared for the president" (Huffington Post, March 5, 2013). According to a senior Israeli security official, the Americans are planning for possible military action against Iran "very seriously." "Obama's administration, as opposed to that of his predecessor George Bush, has prepared a pinpoint military option in the event that the United States decides to attack in the end. The Americans, if they choose, will be able to mount a focused operation on the Iranian nukes without necessarily sparking a comprehensive regional war."

Like an Israeli strike, a U.S. operation would risk angering Arabs and Muslims; however, the reaction to both will also be affected by the success of the operations. Most of the Arab world has made clear it opposes Iran's nuclear program and would cheer, privately if not publicly, the destruction of the threat. Provoking a regime change would also be viewed positively by most of the people in the region. If an operation results in harming the Iranian people, especially if there are high numbers of civilian casualties, the response could be more negative.

If the United States does take military action against Iran, it will probably act quickly to reassure the Iranian people and others in the region that it acted only as a last resort after Iran failed to heed international calls to give up its nuclear weapons program. If there is a change in the regime, it is likely the U.S. would offer aid to encourage a turn to democracy and to help Iran rebuild the non-military areas that were damaged during the operation. American officials may also want to affirm a willingness to help Iran develop a nuclear energy program with appropriate safeguards to ensure that Iran cannot divert nuclear material for military purposes (Haaretz, March 22, 2013).

Following the announcement that a framework nuclear agreement had been reached with the aim of curbiung Iran's nuclear program, international actors were skeptical as to whether Iran would stick to it's obligations under the deal. US Defense Secretary Ashton Carter announced on April 13, 2015, that the Pentagon has a bunker-busting bomb capable of destroying Iran's secretive underground nuclear facilities in order to ensure that Iran does not cheat the agreement and begin to develop a nuclear weapon. The weapon, called the Massive Ordinance Penetrator, is being “continually improved and upgraded” and provides the United States with the capability to “shut down, set back, and destroy” Iran's nuclear program. (The Hill, April 10, 2015)

Multilateral Action

Most of the discussion about the possibility of military action has focused on Israel and the United States; however, it is more likely that an operation will be mounted by an international coalition. One reason to expect this is that President Obama is reluctant to act unilaterally and has made multilateralism a centerpiece of his foreign policy. Furthermore, the countries leading the campaign against Iran have been Europeans, in particular the British, French and Germans. Although none of those countries are likely to act alone, they would probably join a U.S.-led attack. All of these countries oppose a unilateral Israeli attack. As French President Francois Hollande told Israeli President Shimon Peres in March 2013: "France's position is that we should strengthen the economic sanctions against Iran, they are effective, they are working and we have no doubt that if Iran continues to develop nuclear weapons, the international community, not Israel, will bear the responsibility to stop it! Iran is not just a danger to Israel but a danger to the Gulf Region, to Europe and to the whole world" (Algemeiner, March 8, 2013).

Cyber War

Even as negotiations, sanctions and war preparations go on, a covert war is being waged against Iran's nuclear program. This involves efforts to sabotage nuclear-related equipment both before and after it arrives in Iran. One of its most important components has been the use of cyber warfare. In 2010, the world learned that a computer worm referred to as Stuxnet wreaked havoc on Iranian computer systems and led to the destruction or damage of hundreds of centrifuges. In June 2013, news reports revealed that Retired Marine Gen. James “Hoss” Cartwright, a former vice chairman of the Joint Chiefs of Staff, is being investigated about the leak of classified information about the Stuxnet virus (AP, June 28, 2013).

In 2012, Iran admitted that another cyber attack, Flame, infected their computers, this time allowing the attackers to use them for surveillance. Iran's oil ministry was hit by the Wiper program, which erased its hard drives. News reports attribute the cyberwarfare to a U.S. and Israeli intelligence operation called "Operation Olympic Games," started under President George W. Bush and expanded under Obama (New York Times, June 1, 2012). It is believed these covert activities set the Iranian program back months, if not years. Still, these measures did not stop Iran's program and its continued advancement has kept the military option “on the table.”