Concerns that Israel will attack Iran in an attempt to prevent Tehran from developing nuclear weapons escalated Thursday when the Washington Post reported that Defense Secretary Leon Panetta believes there is a “strong likelihood” that Tel Aviv will launch such an offensive in April, May or June. 

Panetta, who is attending a NATO meeting in Brussels, did not dispute the report by Post Op/Ed columnist David Ignatius. 

"No, I'm just not commenting," he said when asked about the report, adding, "What I think and what I view, I consider that to be an area that belongs to me and nobody else."

 

Panetta’s reported view has been echoed in recent interviews by NBC News with current and former U.S. and Israeli officials who have access to their countries’ intelligence. Those officials, all of whom spoke to NBC News on background, estimated the odds of an Israeli attack on Iran as better than 50-50.

But Israel, which has an openly hostile relationship with Iran and much more at stake if its neighbor becomes a nuclear power, is more of a wild card, say the officials, who come from a variety of intelligence and national security backgrounds. But the officials warn that, if intelligence indicated that Iran was on the verge of building a nuclear weapon, the government of Israeli Prime Minister Benjamin Netanyahu would almost certainly consider a military strike. And if it decided to launch one, the U.S. would likely receive very little advance notice, they say. 

Here, in question-and-answer format, is a summary of how the officials see such an attack unfolding: 

 A: Officials agree the chances for an Israeli attack on Iran are at least 50-50, maybe higher. More than one former official has suggested the possibility is as high as 70 percent, but events can move that higher or lower. One said he is “worried sick” about it.

  

Q: When might Israel attack? 

A: Most of those questioned said the prospects of an Israeli attack will increase as the calendar moves into spring and summer. 

Q: What assets would Israel use? 

A: Many of those interviewed claim Israel would launch a multi-pronged attack, using its fighter bombers as well as its Jericho missile force.

 

Israel has both medium and intermediate range Jerichos. The medium-range Jericho I would not have the range to reach many Iranian targets  but the intermediate-range Jericho II’s, capable of hitting targets 1,500 miles away, would have no problem.  The Jerichos would be equipped with high explosives, not nuclear warheads. Asked if the Jericho would have the accuracy and the explosive power to take out a hardened bunker of the sort believed to be protecting Iran’s most-sensitive underground nuclear facilities, one official replied, “You would be surprised at their accuracy” and that the high explosives involved is a special mix of chemical explosives that could conceivably penetrate the Iranian fortifications.

Missile attacks would be coordinated with fighter-bomber attacks (presumably  the Israelis’ extended-range F-15I Strike Eaglet) as well as drone strikes. The fighter bombers would use what one official described as  “high-low, low-high” flight paths -- high first to increase fuel efficiency, then low for most of the trip to evade radar, then climbing high again as the weapons are released in what is known as a “flip toss” on the target.  The Israelis would be prepared to lose aircraft if necessary, the officials said. 

The Israelis are not planning to use submarine-launched cruise missile force -- “not enough of them,” one official said of the subs. (The Israelis have long had nuclear tipped sub-launched cruise missiles as part of their deterrent force.)

  

A: U.S. officials believe that Saudi Arabia and the United Arab Emirates would support the attacks because of the threat Iran poses to them.

 

The Saudis and Emiratis, both of which have Sunni controlled governments, have repeatedly lobbied the U.S. to bomb the Iranian nuclear facilities, preferring a U.S. attack to an Israeli one. But because both are desperate to have someone take out the Iranian program, they also have shared information with the Israelis. If Israel did decide to attack, it’s likely Israeli jets would overfly Saudi territory and would even be allowed to perform aerial refueling. An attack would take at least two midair refuelings.

 

As for Turkey, it may not participate at the same level as the Sunni Arab Gulf states, but it is watching Iran closely. The U.S. fears Turkey would consider a nuclear weapons program if Iran obtained them and could develop nuclear weapons much more quickly than either Saudi Arabia or the UAE.

Q: Would there be a ground component? 

A: Not in a traditional way. Some officials have suggested that Israeli commandos, either from the Israel Defense Forces or Mossad (or both), would be inserted on the ground near targets to illuminate them, gather post-strike forensics and perhaps grab some materials for later analysis. 

Q: What would Israel’s goal be? 

A: Israel would not try to take out every Iranian nuclear facility but instead would target certain facilities it considers critical, hoping to set the program back. U.S. officials believe an attack could put the program back two to four years, Israelis estimate more like three to five. One official said the Israelis are prepared to “do the same in two to four years” if the Iranian program recovers.  

Q: How successful might the attack be? 

A: Iran has fortified its critical underground nuclear facilities with as much as 30 meters (nearly 100 feet) of reinforced concrete, including the centrifuge cascades at Natanz and Fordow outside Qom.  Israel however has dramatically improved its bunker-busting capability over the past three years. 

Israel is unlikely to bomb “soft targets” within the Iranian nuclear program, including labs inside universities or near civilian centers, say U.S. officials. That’s because they are hoping that a clean strike would show that Israel only wants to take out nuclear facilities dear to the mullahs and Revolutionary Guards, both of whom who they believe to be wildly unpopular with the Iranian people.

 

Q: How might Iran respond? 

A: As the New York Times reported Friday, the Israeli military intelligence assessment is that Iran’s military response to such an attack would be muted, in part because of its limited capability and in part because of it understands a massive attack would be met with massive response. Not everyone agrees with that assessment, noting that Iran has had years to plan out their response. The biggest fear is that Iran would unleash Hezbollah, which has between 42,000 and 48,000 missiles and rockets in southern Lebanon aimed at Israel. Even before any attack, officials in both Thailand and Azerbaijan say they have recently thwarted Hezbollah plots against Israeli facilities. 

Israel understands that Hezbollah may respond on behalf of Iran following an attack and is prepared to go after Hezbollah “and not stop at the Litani River (the northern limit of most previous Israeli attacks) this time nor limit its force to a brigade or two” as one U.S. official put it.  Another added that Israeli officials understand that “Israeli blood, Jewish blood will certainly be spilled” in attacks around the world in the event of an attack.  And the response might not be immediate. One official noted that the Saudi Hezbollah attacks on Khobar Towers in 1996 took place months after the U.S. passed tighter sanctions against Iran. 

But another notes that the level of Hezbollah support for Iran in such a scenario is an enormously important – and difficult -- question for both Israel and the U.S.  Hezbollah’s  position is precarious, as Syria -- its main conduit for Iranian supplies – is wracked by violence and its main focus has shifted to governance in Lebanon. Most officials think Hezbollah won’t be able to sit this one out, but few expect a massive response against Israel, which would engender a counterattack by Israeli forces. 

There are other possibilities.  One Iranian says to watch Dubai where 400,000 Iranian expatriates work.  Iranians could “shut it down,” the official said.  All the officials note that Iran has had a long time to plan its response. 

One huge question is what the Iranians would do if they believed that the Saudis or Emiratis were helping Israel.  In that case, say U.S. officials, expect Iran to respond against the southern Gulf States and, if the attack is serious enough, expect the United States to move to protect the Saudi Kingdom in particular, expanding the theater of combat.  

Q: What is the worst-case scenario for the U.S.? 

A: The worst case in case the Israelis attacked Iran would be if the Iranians judged the U.S. had been implicated or involved in the attack. Senior Iranian officials have in the past told NBC News that they would make no distinction between an Israeli attack and a U.S. attack. They see the two working hand-in-hand. 

If that happened, presumably the scope of Iran's retaliation would encompass the U.S. At the far end of the spectrum, they might go an “embassy-a-day program, start blowing up U.S. missions in various cities,” said one former U.S. official. But another intelligence official said such a response would be highly unlikely, noting that even a single embassy attack would mean massive U.S. retaliation. The Iranians also could  attack ships of the U.S. Fifth Fleet in the Gulf or U.S. allies on the Arab side of the Gulf, but either of these responses would likely prompt a U.S. military response aimed at toppling the regime in Tehran, the official said. 

Q: What about oil? 

A: The price would spike immediately, going from around $100 a barrel now to “between $200 and pick-a-number,” said one oil trader.  How quickly it would revert to lower levels would depend on how quickly the situation stabilized and how and where Iran would respond.  An attack on Saudi Arabia, for instance, would place the price target at close to that “pick-a-number” scenario, the trader said. 

Even a $25 a barrel increase would have serious consequences for the recoveries in U.S., European and East Asian economies, particularly Japan.  “It would be a game changer,” for the U.S. economy and the political season, said a U.S. official.  

Q: Why would Israel launch such an attack?  

A: Putting aside Iranian President Mahmoud Ahmadinejad’s inflammatory comments that Israel should be “wiped off the face of the Earth” (which some Iranians claim privately was a mistranslation), some Israeli officials believe the continuous threat of an Iranian nuclear weapon would lead as many as 200,000 of their best and brightest citizens to leave for the United States and other Western nations. That is the “existential threat” Israeli officials worry about, not that Iran could destroy Israel.

An Iranian nuclear weapon would give Israel a lot less latitude to respond to Iranian threats, the Israelis believe.   

A: It may seem cynical, but some in the Middle East think an attack could be timed to the U.S. presidential election. Some in Middle East believe that Israel might carry out an attack at the peak of the U.S. campaign in the belief that candidates and other elected officials in both parties would compete to show their support for Israel.