Gershom Gorenberg is author of The Accidental Empire: Israel and the Birth of the Settlements, 1967-1977 (Times Books)

In late January, the Israeli novelist AB Yehoshua wrote an article in the country's largest-circulation newspaper, Yediot Aharonot, urging the US to temporarily recall its ambassador from Israel. That act of diplomatic pique, he said, would be proof of America's friendship to his country.

The purpose, Yehoshua wrote, would be to pressure Prime Minister Olmert to evacuate the tiny West Bank settlements known as outposts, which violate Israeli and international law. Olmert and his predecessor Ariel Sharon had been promising President Bush to dismantle outposts for over three years. Olmert has publicly said that the country shames itself by not acting, but he fears the violent protests of the outpost settlers. Since most Israelis value good relations with the US, an American show of displeasure would help produce the public backing Olmert needs. "If the US is a true friend of Israel," Yehoshua said, "it must help her through a symbolic act of protest."

Yehoshua is an immense figure in Israeli culture. His novels are canonical. He is outspokenly dovish but firmly within the mainstream left. He is also an old-fashioned Zionist who offends diaspora Jews by saying that one can only live a full Jewish life in Israel. So the man calling for America to lean on Israel is no radical. (In fact, in Israel Yehoshua's article promptly vanished from public notice, presumably deemed unremarkable.)

By asking for a deus ex machina to intervene in Israeli politics, Yehoshua was demonstrating the despair of Israel's peace camp. The left's once-forbidden positions"”a two-state solution, evacuating settlements"”are now boringly respectable. Olmert, a recovering rightist, supports them. But nothing happens. Why can't a winged figure descend to get the plot moving? America has filled that role for Israel before, vetoing UN security council condemnations, providing aid. Someone simply needs to tell the gods what Israel actually needs.

I write this not to mock Yehoshua but to agree with him. As a progressive Israeli, I long to see a shift in US policy. With Yehoshua, I believe that the right actions by the US could awaken public support here in Israel for the steps needed to reach peace.

I also believe there's no chance that President Bush will take Yehoshua's advice. If a member of the US congress made a similar proposal, the American Israel Public Affairs Committee (Aipac) would almost certainly encourage donations to his opponent in November's election. Does this mean that "the Israel lobby" controls the levers of US middle east policy, as John J Mearsheimer and Stephen M Walt argued in their famous book of that name last year? Not exactly. (Mearsheimer and Walt are both distinguished international affairs academics from, respectively, Chicago and Harvard universities. Their book, which caused a storm of criticism and accusations of anti-semitism, argued that US foreign policy is distorted by unconditional support for Israel, secured by a powerful "Israel lobby.") But they overstated their case in several ways. They credited a poorly defined "lobby" with exaggerated power, while failing to do the investigative research which could have painted a more accurate picture of the extent and limits of that power.

So what exactly can we say about Aipac? Along with a small number of other groups, Aipac is widely seen as speaking for Israel and American Jews from within US politics. But Aipac is certainly more hawkish on middle east politics than most American Jews. Though the precise degree of its influence is hard to measure, it is by all accounts"”particularly its own"”an effective lobbier of congress. And it is famously pugnacious when challenged. Yet its relentless focus on Israel's short-term security needs is ultimately damaging to Israel's long-term need for a viable peace deal. Why, then, is there no counter-Aipac, no dovish Israel lobby?

Before trying to answer that question, it is worth trying to establish more clearly how the existing lobby works. Since the real work of lobbying is done behind the scenes, its impact measured in nuances of legislation, a serious researcher would dig through archives and office files and interview lobbyists and congressional staffers to track the process. The researcher would also try to find out what, besides lobbying, shaped US middle east policy. On both counts, Mearsheimer and Walt failed to do the work.

Judging from published reports and Washington sources"”almost all of whom insist on speaking anonymously on this subject"”a proper study would conclude that Aipac has convinced members of congress that they can boost their campaign donations if they favour aid and arms for Israel. It would, further, almost certainly point out that politicians are afraid to add conditions to that aid"”such as reducing aid by the amount that Israel spends on settlements in the occupied territories. The research would also report that Aipac sometimes loses"”as when it failed to keep Ronald Reagan from selling AWACS surveillance planes to Saudi Arabia in 1981.

Lobbyists can only bend foreign relations so far. America's basic interests constrain its policy towards the middle east, yet those interests are neither self-evident nor consistent with one another. The problem was stated over 40 years ago by McGeorge Bundy, who was President Johnson's national security adviser until 1966. When the six-day war broke out in June 1967, Bundy was called back to the White House. A month later, he wrote a nine-page "framework of policy" for US relations with the middle east.

The Bundy doctrine's bottom line is that US interests contradict each other: the US is committed to Israel's survival, but also to good relations with pro-western Arab states that would like America to tilt against Israel. The war showed that US influence is limited; Washington could not even "dissuade some of our best friends among the Arabs from joining in the gang-up" against Israel. Even when Washington disagrees with Israeli policy, Bundy says, it should provide enough arms for Israel to defend itself. For if Israel faced defeat, the US "would confront the"¦ painful and unattractive choices" of whether to send its own troops into battle.

Forty years on, much of Bundy's description remains valid. It is easier, even cheaper, for America to keep Israel strong than to defend it directly. But Washington must also accommodate Arab allies. The Bundy doctrine implies that getting Arabs and Israelis to agree a peace deal would resolve the contradictions in US policy"”and would be the best guarantee of Israeli security. The question then becomes one of how much the US should lean towards providing for Israel's immediate security needs, and how much it should be pushing Israel towards a peace agreement as a strategic solution.

Aipac, according to sources familiar with Capitol Hill lobbying, tries to keep US policy almost entirely on the side of security needs, of protecting an embattled Israel. That's the implication behind Aipac's credo as spelt out on its website, where it describes itself as working "to help make Israel more secure by ensuring that American support remains strong." Aipac does not come out explicitly against peace efforts. But the list of initiatives it boasts of promoting includes nothing aimed at a two-state solution, and much aimed at restricting US relations with the Palestinians and other Arab and Muslim actors. Examples include increases in aid to Israel and a House of Representatives resolution "praising the Jewish state for reunifying Jerusalem" in 1967"”alongside efforts to put conditions on aid to the Palestinian authority and enable sanctions against Syria.

As MJ Rosenberg of the dovish Israel Policy Forum comments, "They create an atmosphere on Capitol Hill that is sceptical of Palestinians in any shape or form." Another knowledgeable source explained to me that Aipac promotes an American stance that the Palestinian side is the one "responsible for what is going wrong, and it has to prove itself first. And if that's always going to be the definition of the peace process, they've killed it from the start."

Aipac has reportedly created hurdles even when the Israeli government itself has tried to make peace. In 1995, for example, Aipac backed a bill in congress to move the US embassy in Israel from Tel Aviv to Jerusalem. The legislation looked pro-Israel. But as Michael Massing argued in the New York Review of Books and elsewhere, it was actually an ambush for Prime Minister Yitzhak Rabin, who was negotiating with the Palestinians. Moving the embassy would have thrown a spanner into the Oslo peace talks. (The bill passed, but with a loophole enabling Presidents Clinton and Bush to avoid the move to Jerusalem.)

Another of the things that a responsible researcher could say with confidence is that within US politics, Aipac does not represent the views of American Jews. In 2004, only 24 per cent of Jews voted for Bush, according to exit polls. Yet when Bush spoke at Aipac's convention earlier that year, delegates reportedly interrupted him 67 times with ovations and chants of "Four more years!"

The liberal Jewish tilt even applies to middle east issues. The American Jewish Committee's most recent year-end survey of Jewish opinion showed a 46-43 plurality of US Jews in favour of establishing a Palestinian state. Support for the war in Iraq is consistently lower among Jews than among Americans in general. The AJC survey showed 57-35 per cent opposition among US Jews to American military action to stop Iran's nuclear programme.

As for Aipac, one of its current legislative concerns is promoting a hawkish position towards Iran. The organisation's website celebrates its role in the passage last year of the Kyl-Lieberman amendment, a Senate resolution on Iran. Among other provisions, the amendment labels the Revolutionary Guards a terrorist organisation. Democratic critics of the resolution say that it could open the door to the Bush administration going to war against Iran. Nonetheless, 76 out of 100 senators voted for it"”meaning it got a majority even among Democrats. That vote came too late for Mearsheimer and Walt to describe, but it raises a big question: how significant is Aipac's role in influencing Democratic lawmakers to take stances apparently to the right both of their constituency and of US Jewish opinion? This is not a rhetorical question; other pressures must be accounted for too, including Democrats' abiding fears of appearing insufficiently muscular.

In any case, Mearsheimer and Walt did not write the sober and balanced book that we need on this emotional subject. Among other things, they described the neoconservative movement as being a subset of the Israel lobby rather than a wider political stream for whom Israel is just one concern"”and whose positions on the middle east sometimes differ sharply from that of the Israeli government. The neocons, for example, thought they could democratise Arab countries; Israeli officials and experts generally fear that democracy will empower Islamic extremists or destabilise their neighbours, and they were ambivalent about the invasion of Iraq.

Yet perhaps the most striking flaw is that Mearsheimer and Walt accept Aipac's own claims regarding its power and who it represents. "In 24 hours, we could have the signatures of 70 senators on this napkin," they quote an Aipac official telling a journalist, and they insist it is not bluster. Though they sometimes note that "the lobby" is not the same as the American Jewish community, they also cite guesstimates that Jews provide between 20 and 60 per cent of donations to the Democratic party and its presidential candidates, and explain this as basic to "the lobby's" influence.

In a strange way, the book thereby becomes an advertisement for Aipac: the organisation's attraction for supporters is the power of its influence over congress and US policy. Its allure to candidates is its influence over Jewish donations and, to a lesser extent, votes. There's a truth here, as we have seen, but there is also a mythic shadow and politicians are sometimes frightened of the shadow. The potential for a counter-Aipac dovish lobby lies, in part, in dispelling fear of the shadow.

The concern of US politicians to stay in Aipac's good books becomes especially clear during election campaigns. Its status as a lobby means it is not allowed to directly raise money for candidates, or to endorse them. Instead, explains Rosenberg, it works closely with "50 to 60" political action committees"”the bodies that actually raise and dispense donations.

One way for a politician to gain Aipac's approval is to publish a position paper on Israel, such as one that Hillary Clinton posted on her website last year. She begins by praising Israel as "a beacon of what democracy can and should be." She asserts that "Israel's right to"¦ an undivided Jerusalem as its capital"¦ must never be questioned." (Israel's vice-premier, Haim Ramon, is among those who supports negotiating a political division of Jerusalem.) She defends "Israel's right to build a security barrier" without mentioning that it runs through occupied territory, meaning Israeli settlements in the West Bank are de facto annexed to Israel. Indeed, the paper contains no mention of settlement, occupation, or helpful changes in Israeli policy. In Israel, it would place her firmly on the political right.

Clinton's rival for the Democratic nomination, Barack Obama, has his own policy statement on Israel, opening with a snippet of a speech he gave to an Aipac forum. Strikingly, though, his paper includes a promise to "work towards two states living side by side in peace and security." Obama has also been more forthright in calling for a shift in strategy towards Iran, including direct talks.

An adviser to Obama's campaign stresses that Aipac has said nothing against the senator. But Malcolm Hoenlein, executive vice-president of the Conference of Presidents of Major American Jewish Organisations, did tell the Israeli daily Haaretz that "there is a legitimate concern over the zeitgeist around the [Obama] campaign," a comment intended to provoke anxiety. Obama has clearly made an effort to show that he can be as pro-Israel as Clinton"”for instance, by sending a letter to US representative at the UN, Zalmay Khalilzad, in January insisting that any security council resolution on the Gaza crisis "clearly and unequivocally condemn the rocket attacks against Israel." The letter said nothing of the Israeli blockade of the Gaza strip. (Speaking to me, the Obama adviser noted that exit polls in the primaries showed his candidate doing as well as Clinton among Jewish voters, perhaps better. But does this mean Obama has convinced Jewish voters that he is toeing the standard line, or are some actually attracted by his hints at a more dovish policy?)

An Aipac blessing undoubtedly matters to some Jewish donors and voters"”those for whom Israel is the overwhelming political concern. But they are a small minority. In the American Jewish Committee's latest survey, only 6 per cent of respondents said that Israel would be the most important issue in choosing who to support for president this year.

The people for whom Israel is the cardinal issue tend to hold strongly right-wing views on Israel and the middle east, and to regard Israel as standing perpetually on the brink of annihilation. And it appears that they dominate discussion of Israel within Jewish organisations, including Aipac itself. Most other Jewish campaign donors support a wide liberal agenda"”on Iraq, the economy, abortion, the environment and more. But in meetings with candidates, they are unlikely to mention their views on Israel.

So the first task of a counter-Aipac would be to be to get dovish Jewish donors"”who support an end to the occupation, a two-state solution and a more active US role in getting there"”to express their views more loudly, so that the politicians cease equating Aipac with Jewish support. A second would be to line up donors willing to make money conditional on more moderate positions on Israel"”willing to meet candidates in well-appointed living rooms with chequebooks and say, "What will you do to save Israel from the occupation?" Hillary Clinton needs to know that she could gain, rather than lose, if her positions did not sound as if they were written by Benjamin Netanyahu.

For over a year, there have been reports that a "liberal Israel lobby" is on the verge of forming. Plans are now apparently well under way for the launch, sources close to the project have told me.

The new group will face many challenges, partly because, as we have seen, liberal Jews in America are more likely to care about general US political issues than about ethnocentric ones. But for a new lobby, I would suggest, the first principle should be that Israel's strategic goal is peace based on a two-state solution with the Palestinians, and that America serves its own needs by helping Israel get there. The mainstream Zionist vision was, and is, of a democratic state with a Jewish majority, with full rights for all citizens, a country living at peace with its neighbours. (That's what Israel's declaration of independence says.) The state should be Jewish simply by dint of that majority, not through discrimination.

There is an unbearable contradiction between this vision and the continued rule of the occupied territories. To leave the Palestinians of the West Bank disenfranchised, under military rule, their daily movements restricted for the sake of Israeli settlers' safety, undermines democracy. On the other hand, annexing the West Bank and Gaza and granting citizenship to the Palestinians means creating a binational state. The conflict between the two national groups within such a single state is likely to look more like Bosnia in the 1990s than Belgium today.

For Israel, therefore, reaching a two-state solution is a strategic necessity. The only way to achieve that is a peace agreement. Israel can safely withdraw from the West Bank only under an agreement in which Palestinians also accept the principle of two states, of partitioning the contested homeland. The Palestinian government must be strong enough to control its territory and prevent splinter groups from continuing armed struggle for all of Palestine. The only workable baseline for a peace agreement is a full Israeli pullout from the West Bank, with some minor exchanges of territory"”so giving up most of the settlements is also a necessity for Israel's future.

Avoiding a single-state outcome is also an American goal. Israel is the one country in the middle east that can be depended on to stay pro-US. This would not be true of a single state which in time would have a Palestinian majority and built-in communal conflict.

So the first priority of a real pro-Israel lobby should be pushing for the most active possible US role in brokering a two-state solution. As Israeli strategic analyst Yossi Alpher has pointed out, the US has succeeded in advancing Arab-Israeli peace only when an emissary representing "the full prestige of the American president" has come to the region for extended negotiations, as Henry Kissinger, secretary of state, did after the 1973 war.

The negotiator has to propose compromises and then push hard for them. The US must also provide incentives. It should offer funds to resettle Palestinian refugees in the Palestinian state and to relocate Israeli settlers within Israel. But the offers should have tough conditions: for the Palestinians, giving up on resettling refugees within Israel; for Israel, evacuating settlements that it has heretofore insisted it has to keep. The liberal Israel lobby should work on Capitol Hill to support such funding for peace.

Diplomacy also means effective pressure on both sides and on the relevant Arab states. The US should insist that the Palestinian authority in the West Bank disarm all armed factions that remain in its territory. But the US will need to lean on Israel too. Right now, the Israeli public has no idea how much the state spends on settlement. American insistence on financial transparency as a condition for current aid levels would serve Israeli democracy and increase domestic backing for a settlement freeze. AB Yehoshua is right that the US should finally show real displeasure that outposts have not been taken down. That's an example of how Washington can help an Israeli government do what it knows it should, helping to beat domestic pressures.

Realistically, even a liberal Israel lobby will be more timid than progressive Israelis. Few US Jews will feel comfortable asking for American pressure on Israel. Publicly, the lobby's task will be to increase support for diplomacy and a two-state solution. But it will also allow more politicians"”particularly liberal ones"”to say what they really think about Israel/Palestine, safe in the knowledge that there is an alternative lobby to back them with money and votes. Quietly, it should counterbalance lobbying by Aipac for congress to tie the president's hands in negotiations. If a peace process really does get moving, expect an Aipac-backed congressional resolution on the need to keep Jerusalem united as the capital of Israel"”an American position that would undermine the talks. The liberal lobby's task would be to push the pragmatic stance that the future of the Holy City must be agreed by both sides.

But a real pro-Israel policy extends beyond the Palestinian issue. Renewed peace talks between Israel and Syria are in both Israeli and American interests. If the talks succeed, they would lead to a cold peace"”which is much better than the current cold war, in which Damascus uses Hamas and Hizbullah as proxies to bleed Israel. Alon Liel"”the ex-director general of Israel's foreign ministry, who last year revealed that he had conducted unofficial back-channel talks with Syria"”says that part of any peace deal would be Syria realigning itself with the west. That would weaken Iran's position in the region, and be a clear American victory. A liberal lobby would promote US backing for such negotiations.

Even on Iran, a liberal lobby could encourage a shift. An Iranian bomb is certainly a serious danger to Israel. But US refusal to negotiate with Tehran means giving up in advance on means to reduce the threat. There are hard-nosed strategic analysts in Israel who advocate a quid pro quo: US acceptance of the Iranian regime in return for an end to uranium enrichment and support for terror groups.

Ultimately, Israel's goal is to be part of the middle east, not to be a garrison state in conflict with it. To support the most bellicose possible Israeli or US policies is to damage both countries. A liberal voice is needed in Washington to press that message. Perhaps this is another form of hope for a deus ex machina. If so, the winged figure is long overdue.