— despite the Administration’s misgivings. The purpose of those sanctions, routinely described as “tightening the noose” by State Department officials, is to choke off Iran’s economy.  In an election year in which painting Obama as weak on Iran is the centerpiece of the Republican foreign policy discussion, and with congressional Democrats far more hawkish on the issue than the White House is, putting the brakes on a sanctions policy to which Iran may respond as if to an act of war carries a heavy political cost to the president.And if sanctions and Israeli air strikes are two potential triggers for war over which the White House has less than optimal control, it may have even less say over the covert war against Iran that could could also provoke full-blown hostilities.

The realization that the Administration’s options are being narrowed by the actions of others may account for the vehemence with which Secretary of State Hillary Clinton last week condemned the murder of an Iranian nuclear scientist in Tehran. The general assumption, both in Tehran and in Western capitals, is that Israel is behind the attacks — a suspicion reinforced by the Israeli response which has been to effectively encourage it without claiming — or denying — responsibility.

Even more alarming, if true, were the claims made in Foreign Policy magazine by military analyst Mark Perry,  last week, alleging that an internal CIA assessment had concluded that Israeli Mossad agents masqueraded as CIA operatives while recruiting members of a Sunni jihadist group to wage proxy operations in Iran. An anonymous Israeli official speaking to Haaretz dismissed the charge as “absolute nonsense,” while U.S. officials did not comment for Perry’s story.

First and foremost among those who could take the decision to start a war out of Obama’s hands, of course, are the Iranians.

“We should not be surprised that a country faced with economic warfare would remind the world that it, too, can create mischief,” warns former National Security Council Iran specialist Dr. Gary Sick. “Iran cannot close the Strait of Hormuz for a prolonged period of time, but it is capable of impeding oil traffic out of the Persian Gulf for many months. The loss of its own oil exports would be the trigger for such action, which would drive up the price of oil to unforeseeable levels and risk a wider regional war.” (Other analysts suggest that closing the strait may be Iran’s trump card, which it would hold in reserve for when it comes under military attack, and might instead seek other methods of retaliation for sanctions pressure.)

Defense Secretary Leon Panetta has repeatedly warned Iran that closing the  Strait, through which some 40% of global oil traffic passes, is a “red line” that would draw a military response. The New York Times reported Friday that the U.S. had used a secret channel to send that same message to Iran’s Supreme Leader, Ayatullah Ali Khamenei. But if the message is simply that Iran had better surrender or else sit still while the West chokes off its economic lifeblood, it might as well haven been delivered through a bullhorn. The key question is whether these “secret channels” are being used to communicate anything besides threats.

Until now, the “diplomatic” conversation between the Administration and Iran has largely been restricted to ultimatums, with neither side showing signs of buckling. Turkey appears to have brokered a new round of talks between Iran and the Western powers plus Russia and China. And Iran has agreed to receive a new delegation of IAEA inspectors (besides those who permanently monitor Iran’s enrichment activities), although the extent of cooperation Tehran plans to offer remains to be seen.

 “The central problem is that this is a zero-sum diplomatic game and each side’s move are inherently dual-use and therefore subject to the most malign interpretations,” warns Shashank Joshi, an analyst at Britain’s Royal United Services Institute. ”Enrichment is seen as synonymous with weaponisation, and sanctions are seen as tantamount to regime change. All the while, Tehran has negotiated in obviously bad faith, but the U.S. has also shown little willingness to take risks or offer up carrots commensurate with the sticks.” Domestic politics on each side also militate against making confidence-building concessions to the others. “That is where we stand,” writes Joshi. “Diplomacy that hasn’t worked, sanctions whose effects are unpredictable, and each side lashing themselves ever tighter to the mast.”

Finding a diplomatic path out of the crisis has become increasingly urgent in the eyes of some in Washington — where the U.S. military establishment believes that a military confrontation will do more harm than good, and will at best only delay Iran’s progress but make weaponization more likely — and in allied capitals. But diplomatic solutions would require compromises unlikely to appeal to more hawkish voices, and getting there would require a protracted process of talking and confidence-building gestures that defy the minutes-to-midnight clock imposed on the standoff by those pressing for tougher action. And the track record of the Iranian leadership suggests that covert warfare and effective sanctions are more likely to push them to respond with escalations of their own rather than with concessions.

For pessimistic hawks — those who believe military action is inevitable, and necessary, unless Iran caves on its nuclear program — squeezing Iran to the point that it initiates such hostilities is not necessarily a policy failure. Asked that question by Yahoo columnist Laura Rozen, Patrick Clawson of the hawkish Washington Institute for Near East Policy explained, “I think it’s heading towards confrontation,” Clawson said. “The whole point from the beginning is if we put pressure on the regime, the Iranians will crack at some point.” If there is to be fight, he explained, it’s preferable that it be initiated by Iran, adding by way of anaology, ”Better to enter World War II after Pearl Harbor.”

Pearl Harbor, of course, allowed President Roosevelt to enter a war he’d been trying to join. But an Iranian equivalent would plunge President Obama, despite himself, into a war he’d hoped to avoid.