Iran is coming under increasing pressure over its nuclear ambitions. The West has offered new incentives to coax Iran into halting uranium enrichment, while the European Union has levied new economic sanctions.  As VOA Correspondent Gary Thomas reports, hovering over the diplomatic process is the implied threat of military action.

Iranian missile on display during military parade in Tehran, 17 Apr 2008 (file)

The Bush administration continues to maintain the Iran nuclear issue can be resolved diplomatically.  But the threat of military action, while never explicitly stated, appears to hang over the diplomatic maneuvering.  Talk of an attack on Iran, which seemed to ebb and flow in recent months, has again surfaced.

Details of a recent military exercise by the Israeli air force were leaked to U.S. and British newspapers, and unnamed U.S. and Israeli officials were quoted as saying the maneuvers appeared to be a possible dress rehearsal for air strikes on Iranian nuclear facilities.  

Some analysts believe the Israeli exercises were aimed at putting pressure on the United States to act against Iran.  

An Iran affairs analyst at the nonpartisan Congressional Research Service, Ken Katzman, says Israel is getting increasingly impatient over the failure to resolve the Iranian nuclear issue.

"Now, obviously, Israel is getting progressively more serious by the day, and that has to be factored in.  I think, Israel is trying to say, 'Well, somebody better do something.  Otherwise, we are going to have to do it.  So why do not you all go ahead and do it?'  I mean, I think Israel is basically signaling that something is going to have to start working very soon," he said.

Military analysts say Israel cannot strike Iran without American cooperation.  A former senior State Department intelligence officer for the Near East and South Asia, Wayne White, points out that Iran is out of the range of Israeli bombers, at least without midair refueling.

"The Israelis at that range have a problem.  Their [air] strike package is limited.  And they would be able to hit certain key nodes of the nuclear infrastructure, but they would not really be able to take it out to a degree that it would be set back many years," he said.

An analysis by the private intelligence firm Stratfor says midair refueling would in all likelihood have to take place over Iraq, and Iraqi airspace is still under U.S. control.  That means, Stratfor says, that the United States would be complicit, even if the official version was that it was a unilateral Israeli strike.

Most analysts concur that attacking Iran would not be a matter of a one-time strike against its nuclear facilities, as Israel did in Iraq in 1981 and more recently in Syria.

The U.S. chairman of the Joint Chiefs of Staff, Admiral Mike Mullen is headed to Israel, where a Pentagon spokesman says he will discuss Iran with Israeli officials, but that that would be one of many issues under review. The spokesman emphasized a preference for diplomatic and economic pressures over military options.

The Washington Institute for Near East Policy just published a paper called "The Last Resort".  It is the first policy paper by a major non-governmental U.S. research institution to publicly examine the strategy and consequences of what it calls preventive military action against Iran.

In a forum introducing the paper, co-author Michael Eisenstadt, emphasized that they do not advocate what he calls "preventive military action" against Iran.  But should it occur, he added, it is likely to be a protracted affair.

"Prevention would entail significant challenges, significant uncertainties, and probably would require multiple strikes over time, if it is to impose significant damage and delay on Iran's program, because different aspects of its infrastructure are running on a different timeline, and because presumably there is a good chance they will try to rebuild.  And, therefore, to ensure the success of the policy, you might have to hit again," he said.

Wayne White, now with the Middle East Institute, says hitting the nuclear facilities would not happen in a first strike.

"We know that the op [operations] plan calls for a huge aerial campaign of 1,500 to 2,000 sorties [aerial missions], which probably in its early stages would be not hitting the nuclear targets.  It would be taking out all of Iran's retaliatory capabilities in the Gulf - anti-ship missiles, the air force, submarines, stuff like that - in order to make sure they do not fire back and start hammering the Gulf states or our fleet units and things like that," he said.

Eisenstadt says success of an aerial campaign cannot be judged merely on the physical damage inflicted. "To measure the success of the policy, the criteria, the real factor, is whether Iran decides to rebuild or not.  That is really the crucial consideration," he said.

White says such an outcome is far from assured, and that an attack may only re-inforce Iran's ambitions to be a nuclear-weapons power.

"The Iranians may be taking a lot of lab equipment, a lot of expertise, planning, things that they can take away, and pocketing it somewhere for the very purpose of reconstituting and going for a nuclear weapon if they are hit," he said.

Analysts add that Iran could retaliate in any number of ways, including through terrorist attacks on U.S. and Israeli civilian targets and attacks on U.S. troops in Iraq.