As the Iranian nuclear program nears its critical stages and the possibility of military action becomes more realistic, highly respected observers – even former senior Israeli officials – have come out strongly against this. US President Barack Obama has made his preference for continued sanctions and diplomacy clear. The US and EU talks with Iran on Saturday did not provide a clear indication of whether Iran is serious about wanting a last- minute deal. The inveterate optimism of diplomats aside, the only clear outcome is a further time gain for Iran, until the next round on May 23.

The US should be willing to offer Iran a generous deal that will address its legitimate interests – even the long-sought assurance that the US will not pursue a regime change. For Israel, painful compromises – such as acquiescence to Iran’s long-standing relationship with Hezbollah – are worth making if they achieve the over-arching goal of preventing a nuclear Iran.

No one disputes that an attack should be considered only as a last resort and would be deeply problematic even then.

All sides greatly prefer a diplomatic outcome, and no one more than Israel, whose interests are most deeply effected and which will bear the brunt of an Iranian retaliation.

For a deal to work, however, one has to have a partner. The simple fact is that Iran has rejected all efforts to reach a negotiated solution to date, beginning with Clinton and renewed with greater emphasis by Obama, and has used the passing time to further develop its nuclear capabilities.

We can hope that the punishing oil and financial sanctions now in place will finally change the Iranian calculus.

Giving the sanctions time to work is certainly the preferred option and Prime Minister Binyamin Netanyahu has indicated his willingness to do so. So there still is a limited window for diplomacy, but let us not delude ourselves. Iran has good strategic reasons for seeking nukes, has turned the issue into a domestic cause célèbre, and has so far demonstrated a clear willingness to pay the attendant costs. Hope is important, but is not a substitute for hardheaded policy.

Moreover, there is a fundamental weakness in the argument for diplomacy and sanctions, which reflects a basic unwillingness to face up to the bitter truth and draw the consequent conclusions, painful though they may be: Unless a very unexpected change takes place in Iranian policy, ongoing diplomacy risks becoming a cover for acquiescence to a nuclear Iran and de-facto support for a policy of deterrence and containment.

Although Obama has officially disavowed this option, many believe it to be the likely and even desirable outcome, given the alternatives.

Those who do have the responsibility to say so clearly and openly, not by holding out the probable chimera of a diplomatic resolution.

Military action is certainly not a panacea. Iran already has the know- how needed to reconstitute the program, if attacked, and could reach its current stage of development again within a few years. A gain of a few years, however, should also not be dismissed.

Much can happen in the Middle East in a few years.

For an attack on Iran to make sense, anyone willing to act once would have to be willing to do so again, should the program be reconstituted.

Following an attack, the international community would presumably exert crushing pressure on Iran, in order to deal with the issue and prevent the likelihood of a further strike. Moreover, the time gained would be used for a variety of additional delaying measures, such as renewed subversion, and the long hoped for regime change in Iran might also take place.

Some argue that an attack will merely rally the Iranian people around the regime, which is indeed a likely short-term result. There is, however, no reason to presume that this will be the case once the initial fury passes and Iranians truly consider their interests, especially if the international community continues to impose heavy costs. It should be remembered that the regional uprisings began with the demonstrations in Iran in June 2009.

Diplomacy and sanctions should be pursued during the coming months, while the window of opportunity for doing so still remains open.

Ultimately, however, the choice will come down to one of two danger- fraught alternatives: living with a nuclear Iran through containment and deterrence, or military action. Whichever approach one favors, we owe it to ourselves to face up to this painful choice honestly.

The writer, a Senior Fellow at Harvard’s Kennedy School, was a deputy national security adviser in Israel. (© 1995-2011, The Jerusalem Post 04/16/12)