Israeli national security strategy is founded on the premise that Israel cannot afford to lose a single war. Because the best way to avoid losing a war is to not fight it in the first place, Israeli strategy begins with the maintenance of a credible deterrent posture, which includes the willingness to carry out preemptive strikes. Should deterrence fail, Israel would seek to prevent escalation, and determine the outcome of war quickly and decisively. Since it lacks strategic depth, Israel must prevent the enemy from entering its territory, and must try to quickly transfer the battle to enemy territory.
http://www.globalsecurity.org/military/world/israel/iran.htm
In May 2003, Ephraim Asculai, a former Israeli Atomic Energy Comission official, in an article written for the Jaffee Center for Strategic Studies, wrote that "nuclear verification is clearly failing in Iran, when (the IAEA) let Iran proceed with its ambitious program. In any case, it would be unable to deter or stop its development of nuclear weapons. The verification mechanisms will fail by not being able to prove anything, since intentions, particularly when based on legal actions, are unverifiable."
The annual intelligence assessment presented to Israel's Knesset on 21 July 2004 noted that Iran's nuclear program is the biggest threat facing Israel, "Maariv" and "Yediot Aharonot" reported on 22 July 2004. Some Likud and Labor Knesset members subsequently called for a preemptive strike against the Iranian nuclear facility. Former Deputy Defense Minister Ephraim Sneh (Labor) said, "If the international community's helplessness in the face of the Iranian threat persists, Israel will have to weigh its steps -- and soon." Ehud Yatom (Likud) said, "The Iranian nuclear facilities must be destroyed, just as we did the Iraqi reactor. We must strive to attain the ability to damage and destroy any nuclear capability that might be directed against Israel." On 08 September 2004 Israeli Prime Minister Ariel Sharon said the international community has not done enough to stop Iran from developing a nuclear weapon and warns that Israel will take its own measures to defend itself. He also said Iranian officials have made it clear they seek the destruction of the Jewish state. Israeli Air Force pilots have been practicing attacks on a scale model of the Bushehr reactor in the Negev Desert.
In October 2004 Ephraim Kam, the deputy head of the Jaffee Center for Strategic Studies said that "It would be a complicated operation. In order to undermine or disrupt the Iranian nuclear program, you would have to strike at least three or four sites ... Otherwise the damage would be too limited, and it would not postpone the program by more than a year or two, and this could in the end be worse than doing nothing." Shai Feldman, also at the Jaffee Center, said "There is a logic to operating against Iran even if the location of every facility is not known, because just taking out the facilities that are known, especially if they include the enrichment and heavy water plants, would in itself create a serious degradation of the Iranian potential."
The Israeli Air Force received the first two of 25 F-15I [I for Israel, no Iran] Ra’am (Thunder) aircraft, the Israeli version of the F-15E Strike Eagle, in January 1998, and as of early 2004 had an inventory of 25 aircraft. According to the Israeli Air Force, this aircraft has a range of 4,450 km, which equates to a combat radius of 2,225 km. Deliveries of the F-16I Sufa (Storm) began in early 2004. This heavily modified aircraft, with massive conformal fuel tanks, has a reported combat radius of 2,100 km. Probable strike targets such as Bushehr and Esfahan lie about 1,500 km from Israel.
The 2,060-km strike on the Palestine Liberation Organization's headquarters in Tunis in October 1985, in retaliation for the murder of three Israelis on a yacht in Cyprus, was the IAF's furthest attack from home to date. The F-16s which bombed the Iraqi reactor in 1981 were not refueled and returned home on their last drops of fuel.
On 21 September 2004 Israel acknowledged that it was buying 500 BLU-109 bunker-buster bombs, which could be used to destroy Iran's nuclear facilities. The bombs, which can penetrate more than 7 feet of reinforced concrete, are part of a $319 million package of air-launched bombs being sold to Israel under America's military aid program.
The German magazine Der Spiegel reported in October 2004 that Israel had completed plans for a pre-emptive strike against Iran's nuclear facilities. Der Spiegel reported that a special unit of the Mossad had received order in July 2004 to prepare a detailed plan, which had been delivered to the Israeli Air Force. The source for the report, an IAF pilot, said the plan to take out Iran's nuclear sites was "complex, yet manageable." Israel's plan assumes that Iran has six nuclear sites, all of which would be attacked simultaneously.
It would be difficult for Israel to strike at Iran without American knowledge, since the mission would have to be flown through American [formerly Iraqi] air space. Even if the United States did not actively participate with operations inside Iranian air space, the US would be a passive participant by virtue of allowing Israeli aircraft unhindered passage. In the eyes of the world, it would generally appear to be a joint US-Israeli enterprise, any denials notwithstanding. Indeed, it is quite probable that Iran would not be able to readily determine the ultimate origins of the strike, given Iran's relatively modest air defense capabilities. Thus, even if the strike were entirely of American origin, Israel would be implicated. When asked in August 2004 about Israeli threats to attack Iran, Bush's national security adviser Condoleezza Rice, declined to say whether the United States would support such action by Israel.
In an 08 September 2004 interview in the "Jerusalem Post" newspaper, Israeli Prime Minister Ariel Sharon says the international community has not done enough to stop Iran from developing a nuclear weapon and warns that Israel will take its own measures to defend itself. Sharon said there was no doubt that Iran is trying to obtain nuclear weapons and is doing so by "deception and subterfuge." He said international efforts to curb Iran's nuclear ambitions had not been sufficient. Sharon calls for increased pressure and supervision of Iran's nuclear program and said the issue should be brought before the UN Security Council for sanctions to be levied against Tehran. Sharon said Israel would take steps to defend itself against the Iranian threat. He did not elaborate.
Even though the uranium facility at Natanz has been buried underground, it remains vulnerable. As Lieutenant Colonel Eric M. Sepp noted, "The "cut-and-cover" facilities are constructed by digging a hole, inserting a facility, and then covering it up with dirt and rocks. These cut-and-cover facilities can be just below the surface of the ground or may reach a depth of perhaps 100 feet, and represent the vast majority of underground facilities today. In the case of contemporary cut-and-cover facilities, there is no question that conventional munitions can defeat them."
The air strikes option does have the same problems that one would face in North Korea, namely that Iran has a rather significant air defense capability which could complicate use plans. However, unlike North Korea, Iran is not in a position to hold US soldiers or allied civilian populations (Iraq) hostage. A full-scale Iranian military retaliation, though possible, is highly unlikely, especially with the significant US force presence in Iraq. It is possible that Iran could use its ballistic missiles to strike US or allied targets throughout the Persian Gulf region, and in fact Iranian officials have explicitly promised to do just that.