Back in the spring of 1975, when I was a young reporter for a Dow Jones newspaper called The National Observer, I was invited into a hotel suite in Bethlehem, Pennsylvania, for an evening of conversation and Scotch with Dean Rusk, then about seven years past his tenure as secretary of state under presidents John Kennedy and Lyndon Johnson. Those were tough times for America, led by President Gerald Ford following Richard Nixon’s resignation in the demoralizing Watergate scandal. South Vietnam had just fallen to the North, and the country was suffering economic pain, attributable in part to spiraling oil prices imposed by Mideast exporters enraged by U.S. support for Israel in the 1973 war. Ford’s standing was harmed further by his controversial decision to grant conditional amnesty to Vietnam-era military deserters.

At one point in the conversation Rusk pondered America’s Mideast predicament—committed to Israel as friend and ally for very powerful reasons but finding itself facing unpleasant economic consequences stemming from Arab angers over that support. Rusk speculated that U.S. presidents would have a tough time persuading the country’s young men to fight on behalf of Israel if the war didn’t coincide with American interests. “I think what they will say is, ‘No, thanks; I’ll take some of that amnesty instead.’”

While Rusk’s political assessment contained a certain flippancy, his expression is worth noting as public speculation mounts that Israel likely will attack Iran if it can’t get America to do the job. Much has been written about the geopolitical consequences of such a strike, about the military repercussions, the possible regional destabilization, the prospect for major economic dislocations, the subsequent drain in U.S. blood and treasure. The debate has been lively and healthy. Matthew Kroenig, a fellow at the Council on Foreign Relations, gained widespread notice with his Foreign Affairs article arguing that an Israeli military strike would be far less dangerous than letting Iran build a nuclear capacity. Georgetown’s Paul Pillar countered in these spaces, as others did elsewhere, that Kroenig’s assessments overemphasized the threat of a nuclear Iran while minimizing the aftereffects of a military assault. More recently, writer Eric S. Margolis argued here that an Israeli attack would draw America into a war that isn’t in U.S. interests and that the country can’t afford.

But what would be the impact on the U.S.-Israeli relationship? That question has received almost no attention.

Probably the impact would be minimal if Israel managed to stage a clean series of strikes that actually set back Iran’s nuclear program by, say, three years, without serious retaliatory actions and without nasty geopolitical and economic consequences in the region or the world. But there is simply no chance that that would be the outcome. Iran would not be docile in the face of such an attack. It would retaliate, quite possibly by seeking to close the Strait of Hormuz, through which flows 20 percent of the oil traded worldwide. But it certainly would lash out at its enemies, possibly including the United States. It could seek to destabilize the entire Middle East and exploit the resulting regional chaos in order to enhance its geopolitical position in its neighborhood.

One thing we know about war is that all planning goes out the window once the shooting starts. This would be no exception. And so the consequences are likely to be far more dire and far more costly than Matthew Kroenig is willing to accept. The crisis would likely require the application of American power to restore order to the region and thwart the almost inevitable economic dislocation—stemming from a significant spike in oil prices—from becoming a global depression. This could mean major American military operations—naval combat in the Gulf, massive air strikes to hinder Iranian retaliatory actions, perhaps even ground troops on a major scale.

If this indeed were the result, is it reasonable to assume that the U.S.-Israeli relationship would be unaffected by Israeli actions that spawned such devastating results?

The underlying question surrounding the relationship is whether the interests of the two countries can or actually do diverge significantly. That was the essence of the controversy that surrounded publication of the 2007 book by John Mearsheimer and Stephen M. Walt, The Israel Lobby and U.S. Foreign Policy (an expansion of an earlier magazine article). They argued that those interests can and do diverge and that some U.S. groups supportive of Israel have undermined American foreign-policy interests, particularly in nudging America into the Iraq War. Such arguments threaten the concept of the U.S.-Israeli "special relationship," and that’s why they get furious pushback from many staunch supporters of Israel.

But if Israel were to draw America into a war it didn’t want and for which the cost ended up being politically untenable, then this debate could enter an entirely new phase. The American electorate, which has not been particularly engaged on the matter so far in any emotional way, would almost inevitably enter the fray with a new degree of attentiveness. Then it would become much more difficult to press the argument that the special relationship rests upon an ongoing and unbreakable convergence of interests.

Already, there is more debate on the matter than was seen before the Mearsheimer-Walt book appeared. As Newsweek’s Justine Rosenthal, former editor of The National Interest, told writer Robert D. Kaplan recently, that article and book "changed the debate on Israel, even if it did not change the policy." The authors were attacked at the time as lousy scholars and (by some) as anti-Semites. And yet, barely five years later, the respected Kaplan produced a highly favorable profile of Mearsheimer for the impeccably liberal Atlantic (though Kaplan’s piece was not without criticism). As Kaplan wrote, "The Israel Lobby contains a fundamental analytic truth that is undeniable: the United States and Israel, like most states, have some different interests that inevitably push up against any enduring special relationship."

Now consider the brouhaha that ensued after New York Times columnist Thomas Friedman tossed off a line raising questions about the twenty-nine standing ovations received by Israeli prime minister Benjamin Netanyahu during an address to Congress last May—following a clear effort by Netanyahu to diminish President Obama during a White House meeting. Friedman wrote that he hoped Netanyahu "understands that the standing ovation he got in Congress this year was not for his politics. That ovation was bought and paid for by the Israel lobby."

This was heresy, and the reaction was swift and harsh. Former government official Elliott Abrams said Friedman owed an apology to "hundreds of members of Congress who spoke for their constituents." New Jersey’s Democratic representative Steven Rothman said the expression should be seen as "aiding and abetting a dangerous narrative about the US-Israel relationship." A Commentary writer named Jonathan S. Tobin noted that, because Friedman disdains the uncritical attitude of some Republicans toward Israel, he has to justify his views by "having to paint Israel as being intrinsically unworthy of any support." Tobin also said Friedman represented what he called "the new anti-Semitism."

Leaving aside Tobin’s seemingly purposeful misrepresentation of Friedman’s view of Israel (he is, after all, consistently and ardently supportive), these expressions reflect the almost desperate desire on the part of some Israel supporters to protect at all costs the concept of the special relationship. Note Abrams’s insistence that those standing and clapping members of Congress were acting in behalf of the equally emphatic sentiments of the American people. Note Rothman’s concern about the "narrative" of the U.S.-Israel relationship. And note Tobin’s zeal in employing the hoary "straw-man" approach to discourse (not to mention his resort to the anti-Semitism ploy against a pro-Israel Jew). All this reflects an ongoing ideological necessity on the part of some to protect and preserve the underlying assumption of the special relationship—convergence of interests.

But suppose the already war-weary American people were to find their country in a beleaguered situation—beset by economic woes wrought by a global recession; pulled into further Mideast hostilities that generated growing numbers of U.S. casualties without an end in sight; grappling with an enflamed Middle East that threatened to fray the global order at various points around the edges of its stability. And suppose all this could be attributed to an Israeli military action undertaken over the objections of the American president.

The result would be an entirely new political environment in America for the U.S.-Israeli relationship. When a Mearsheimer or a Friedman spoke up about the divergence of interests between the two countries, the Abramses and Rothmans and Tobins would not be responding with quite the same outrage and aggressiveness. Members of Congress would not be bestowing twenty-nine standing ovations upon Israeli leaders who had just insulted the American president; and, if they did, few indeed would buy the argument that those ovations reflected political sentiment across the country. For a majority of Americans, the idea of an ironclad convergence of national interests between Israel and the United States, in all times and all circumstances, would be seen as not only wrong but dangerously so.