Israel has launched such long range air strikes before. In 1981, Israeli warplanes bombed the Iraqi nuclear reactor at Osirak, and in 1985, Israeli warplanes flew 2,000 kilometers to Tunisia, and bombed the Palestinian Liberation Organization headquarters, in retaliation for a Palestinian terror attack on Israelis. But today, Israel has a new generation of long range bombers (the F-16I and F-15I) that could take out the numerous locations involved in developing Irans nuclear weapons. Israel also recently received 500 American deep penetration bombs, for destroying underground facilities. Although Irans nuclear reactor is operational, the Israeli attack would not have to destroy the containment dome (and release radiation) to knock the facility off line for months. Bombing many of the support facilities around the nuclear reactor would do that.
All of the Iranian targets are within 2,000 kilometers of Israel. Israeli air power is strong enough to overfly Jordan, and deal with any Jordanian opposition. In Iraq, the only anti-aircraft missiles are American, and it is doubtful that they would be fired at Israeli aircraft. Even if they were, Israel probably has the means to defeat the missiles (as Israel uses the same anti-aircraft missiles, and knows exactly how they work.) Israel has no problem getting jet bombers over Iran.
Neither Europe nor the United States wants Iran to have nuclear weapons, but neither Europe nor the U.S. would resort to bombing. They dont have to. Israel is the obvious first target of Iranian nukes, should it ever come to that. So Israel would be the first to attack Irans nuclear program. And Israel is best qualified to make such an air strike.
The major unknown is; would Iran attempt to use their nuclear weapons on Israel? Iranian public pronouncements make it clear that such a rash move is seriously considered. Should Israel hold its fire on the assumption that even the Iranian Islamic radicals would not be so foolish as to start a nuclear war. The Iranian governments official positions is that; it is not developing nuclear weapons, and, even if it had them, they would only be used defensively. That is, if someone, like Israel, attacked Iran, then Iran would nuke Israel in retaliation.
All this puts Israeli politicians in a difficult position. To trust in Iranian reasonableness is risky. Saddam Hussein built long range missiles, and eventually fired them at Israel in 1991, even without nuclear warheads. Saddam was not a religious fanatic, but a calculating, secular dictator. Saddam could have used chemical warheads, but he didnt. The U.S. has made it widely known that anyone who uses chemical weapons on American troops risks nuclear retaliation. That seems to have worked so far, and Saddam may have felt that the Israelis were playing by the same rules. Moreover, making ballistic missile warheads for chemical weapons is more difficult, in some ways, than for nuclear weapons. Iran could also fire their ballistic missiles carrying "dirty bomb" (nuclear material to be spread wide by explosives) warheads. But this would cause few injuries, and cause Iran to be labeled a "nuclear aggressor."
Iran has apparently obtained, from Pakistan, the details of how to build a nuclear weapon. All Iran needs now is the high grade nuclear material. Iran is in the process of producing this enriched uranium, despite protests from the European Union, the UN and the United States. Iran could have its first nuke in six to twelve months. If Israel is going to attack, it will be before the bomb is assembled. Iran recently tested a ballistic missile (the Shahab-3) that could reach Israel. It would take several years to do the engineering work necessary to build a nuclear warhead that would work on their ballistic missile. Unless, of course, they got some help from Russia (which has been selling Iran lots of weapons and nuclear technology.)
Once Iran has the bomb, what will Israel do? Even Israel is not sure, but a large scale bombing raid, perhaps several raids, are quite possible. Currently about 40 percent of Israelis favor bombs over diplomacy. The percentage favoring bombs is increasing. Unless Iran backs off on its nuclear bomb program, the Israelis will probably strike.
Iran is apparently determined to have nuclear weapons, and Israel may go to war with Iran in the near future to prevent that from happening. Long a regional superpower, Iran does not want nukes simply to reinforce its historically dominant position in its neighborhood. Since 1979, Iran has been run by Islamic radicals who, among other ambitions, wants to see Israel destroyed. Logically, it would make no sense for Iranian Islamic radicals to nuke Israel. Its well known that Israel has nuclear weapons, and several ways to deliver them. A nuke from Iran would risk several in return from Israel. And one or two Iranian nuclear warheads would not destroy Israel, while several nuclear weapons would cause enormous damage to Iran. Israel has made it known that if Iran gets close to having a nuclear weapon, Israel would launch air strikes and bomb dozens of industrial sites that are part of the Iranian nuclear program.