Israeli F-15s on maneuvers, showing their external fuel tanks for longer range. Photo: Wikipedia Commons

There is a chance that Israel may attack Iran before the U.S. presidential election, perhaps sometime this fall.

Not a certainty, but certainly a possibility strong enough to warrant careful consideration of the consequences and repercussions (Foreign Policy Magazine is suggesting that a post-election or early 2013 strike is more likely).

Hawkish elements in Israel, including Prime Minister Benjamin Netanyahu and Defense Minister Ehud Barak, are arguing that sanctions and diplomatic pressure from the U.S. and the international community have been largely ineffective in slowing Iran's nuclear development.

On March 5, Netanyahu said during a visit to Washington that "We've waited for diplomacy to work. We've waited for sanctions to work. None of us can afford to wait much longer. As Prime Minister of Israel, I will never let my people live under the shadow of annihilation."

Although experts in the West are still divided over whether Iran's nuclear program is meant to develop a nuclear capability with the potential to eventually produce nuclear weapons; actual nuclear weapons; or just plain nuclear power for civilian use, no Israeli government would want to go down in history as the one that allowed Iran's development of nuclear arms, even if only as a possibility.

In November 2011, Barak said the opportunity for attacking Iran would close within nine months. In February, the Washington Post claimed that U.S. Defense Secretary Leon Panetta thought the attack would occur as early as April, May or June -- revealing of a level of uncertainty even within the U.S. administration about Israel's plans.

Hardliners in Tel Aviv warn that a "window of opportunity" to use military force to severely cripple or set back Iran's nuclear program is quickly closing; given more time, military preparations and nuclear development in Iran may already produce the requisite materials and technologies needed to assemble a device.

Opponents of the military option say the move could even further destabilize an already fragile region (see Syria, Egypt, Lebanon, Iraq, for example) and jeopardize the global economic recovery. A larger war could drag the U.S. back into a costly Middle Eastern conflict, and cement Iran's animosity towards the West. Tehran, in turn, could decide to strike out at U.S. targets throughout the Middle East and Central Asia. Worse, it could embolden future development of nuclear arms.

The Targets

Israel will need to severely damage some or all of four major nuclear sites in Iran. The country has seven known and suspected sites in total (including a light-water reactor at Bushehr, started by the Germans, completed by the Russians). However, sites linked to its fuel cycle and uranium enrichment process are considered key targets for delaying its nuclear development.

Natanz, in central Iran, holds some 9,000 uranium enrichment centrifuges (according to the International Atomic Energy Agency) within a steel, concrete, and earth-reinforced underground structure. Although most of the activity at the site is thought to be geared towards enriching uranium-235 to 5% purity, usable as commercial-grade fuel for civilian power, parts are now suspected of being able to enrich up to 20% purity, enough for a low-yield crude nuclear weapon. Centrifuges are fragile, and shaking and bumping, such as is produced from explosives, could ruin them.

President Ahmadinejad visiting uranium enrichment facilities at Natanz in 2008. Photo: Reuters

Fordow, built under a small mountain near the city of Qom and thought to be additionally hardened when compared to Natanz, may hold as many as 3,000 centrifuges. The IAEA believes the site can produce both 5% and 20% enriched uranium. Although the site is smaller than Natanz, it is far more deeply buried, and may be near-impossible to hit directly with the munitions currently known to be possessed by Israel.

Located at Esfahan, also in central Iran, is an above-ground uranium conversion facility that turns uranium oxide into uranium hexafluoride gas, the substance used in centrifuges to produce enriched uranium-235.

Arak, southwest of Qon, is the location of an above-ground heavy water reactor currently being constructed. Heavy water reactors are considered to be of greater risk to non-proliferation organizations since they do not need to use enriched uranium, and produce greater amounts of radioactive byproducts like plutonium and tritium that can be used in nuclear weapons.

The Strike

An Israeli operation would predominantly rely on its renowned air force, but may also call on its highly-trained special operations forces, innovative cyberattacks, and perhaps limited use of its ballistic missiles.

A strike on Iran's facilities would likely involve the most modern of Israel's long-range warplanes: the country has 25 Boeing F-15I and 100 Lockheed Martin F-16I fighter-bombers, both modified versions of U.S. jets, as the "i" for Israel in their model names indicates. Abdullah Toukan and Anthony H. Cordesman at the Center for Strategic and International Studies, a Washington think-tank, estimated in 2009 that simultaneous strikes on Natanz, Esfahan, and Arak would require some 90-100 planes. That would be almost the entire total of the Israeli's advanced front-line jets.

Fighters would likely be accompanied by up to a dozen mid-air refueling planes, as well as electronic warfare aircraft to help blind or sabotage Iranian air defenses and communications.

The F-15Is could carry one GBU-28s each, a 5,000 pound bunker-busting bomb thought to have the ability to penetrate defenses at Natanz. The depth of Fordow presents a trickier problem.

A U.S. Air Force F-15E releases a GBU-28 bunker buster on a U.S. training range, in 2003. Photo: Reuters/ USAF

Only the U.S. is known to have a conventional bomb capable of directly damaging the facility, the newly developed GBU-57 Massive Ordnance Penetrator, a 30,000-pound weapon designed to dig deep into earth and concrete to destroy buried facilties. The U.S. has not provided the GBU-57 to Israel. However, attacks on ventilation and entrances to the site can still close it down and do major damage.

Above-ground facilities would only require one to three bomb strikes to be destroyed. Israel also possesses the Jericho II ballistic missile, which may allow air power to be directed against underground facilities while the long-range missiles hit above-ground buildings. Open source information however does not reveal the accuracy of Israel's ballistic missiles.

Israel has used air strikes twice in the past to remove nuclear facilities from other countries in the region. In 1981, it obliterated Iraq's Osirak nuclear reactor, then being constructed by France. In 2007, it destroyed a nuclear site in Syria at al-Kibar, suspected of being built by North Koreans.

In the 2007 case, a small-sized group of Israeli jets, thought to be just a half dozen, penetrated Syrian airspace at nighttime, largely undetected, while special operations teams already on location painted the facility with lasers to direct the planes' munitions. David Fulghum of Aviation Week and Space Technology (and many others) suspect that Israel used cyberattacks to penetrate and fool Syrian radars and air defenses.

An operation against Iran may see similar methods deployed. But Israeli planes are not stealthy, and a larger number (like the 100-strong group envisioned above) would show up far more easily on Iranian radars. The Israeli planes would also need to transit through the air spaces of Turkey, Syria, Iraq, Kuwait, and/or Saudi Arabia. Acquiescence to Israeli air forces transiting their air spaces may result in Iran seeing those nations as potential targets in a reciprocal attack.

The Defenses

A MiG-29 in the Islamic Republic of Iran Air Force, dating to 2011. Photo: Wikipedia Commons.

Much of Iran's air defenses are based on missiles bought from the West in the early 1970s and on dated systems from the Soviet Union. It terms of surface to air missiles, it has the Hawk from the U.S. (150 systems), the Rapier from the U.K. (30 systems), and the SA-5 from the USSR (200 systems). Iran also has 30 Gauntlet (known in the West as SA-15) missile systems from Russia, used to shoot down planes at low and medium altitudes, but the far more feared high-altitude S-300 (or SA-10) was never delivered in any significant number from Moscow. Iran says it has produced local equivalents to the above weapons or upgraded the older ones with modern communications, but the claim is difficult to verify. The country also has hundreds of anti-aircraft artillery and smaller, man-portable anti-aircraft missiles.

Air defenses need to be dispersed across the country and would be difficult to redeploy on short notice. Israeli bombing would likely make at least some effort to suppress ground defenses before moving to targeting facilities. Any gap in defenses could be used by attacking forces as a point to concentrate and fly through.

Iran has more than 300 combat planes, according to 2012 data from the International Institute for Strategic Studies, a British think tank. A very limited number of these are indigenously developed planes, but the country still operates the American F-14 Tomcat (approximately 44 planes), F-4 Phantom II (~65), and F-5 Tiger (~60), originally sold to the country before the fall of the Shah in 1979. Russia sold the country the MiG-27 (24 jets operational) and MiG-29 (40) in the early 1990s.

Those planes are unlikely to match the well-maintained and newer Israeli planes, which are also piloted by some of the world's most skilled pilots, but could play a significant role in complicating or foiling an already complex operation.

The Retaliation

Iran testing a Shahab-3 missile. The Shahab-3 has a range of 1,200 miles, capable of hitting all of Israel. Photo:

Iran's best bet to convince Israel (or get the U.S. and others to convince Israel) against an attack may be its professed ability to retaliate. It may have as many as 100 medium-range ballistic missiles capable of hitting Israel. Tehran is also thought to have supplied Hezbollah, based in Lebanon, with tens of thousands of rockets and missiles capable of hitting various areas throughout Israel. Although Israel has three different missile defense systems -- the Arrow, Iron Dome, and Patriot -- none have been tested against the possibility of facing a massive barrage from small, medium, and large missiles.

Iran could seek to launch a "multifront" war against Israel through its local proxy organizations, from missile strikes, and through attacks on Israeli targets elsewhere in the world.

Iran may also choose to attack U.S. forces in the Persian Gulf or Afghanistan, either through direct strikes or other means (such as terrorist bombings) as a means of directing its anger to Israel's key ally.

Missile strikes could be launched against U.S. ships, carriers, and bases in the region, using Iran's thousands of cruise and short-range ballistic missiles. Over 10,000 U.S. personnel still remain in Iraq, where Iran has close ties to influential Shiite militia. 90,000 U.S. forces are deployed in Afghanistan -- Iran could make their task of stabilizing the country much more difficult by directing weapons and training to local insurgents there.

Iran has threatened on numerous occasions that it would try to close down the Straits of Hormuz, a major transit point for global crude oil shipments - some 40 percent of the globe's oil leaves the Middle East from Hormuz. While U.S. forces could eventually (some analysts say easily) clear the Straits of mines, anti-ship missiles, and Iranian vessels, the shock to oil and financial markets may push the global economy back into recession.

Perhaps more distressing for U.S. forces around Iran, as well as for the Obama administration, would be the prospect of being pulled into another extended conflict against a major Middle Eastern state.