On Tuesday, when Secretary of State John Kerry appeared before the Senate Foreign Relations Committee, the questioning from his former colleague John McCain was surprisingly mocking. Kerry and McCain are both Vietnam veterans (and failed Presidential candidates), and had been known to be friendly. But McCain said he was “gravely concerned about the consequences of America’s failure to lead in the world.” Israeli-Palestinian negotiations had collapsed; McCain chalked up their failure, and that of diplomacy with Syria and Iran—what he called Kerry’s “trifecta”—to weakness. Kerry was “talking strongly and carrying a very small stick.”

Kerry responded, sighing, that everything looks failed when it is half done. The Israeli-Palestinian talks, he said, were thrown into crisis because of Israel’s refusal to release a last batch of Palestinian prisoners, prompting President Abbas to apply for membership in fifteen United Nations agencies and conventions, to which Israeli Housing Minister Uri Ariel responded by announcing seven hundred and eight new apartment units in East Jerusalem—at which point, poof, negotiations collapsed. Neither party had been constructive, yet both continued to ask for intercession. Kerry told McCain, “You declare it dead but the Israelis and the Palestinians don’t declare it dead.” McCain had his opening: “It’s stopped. It is stopped. Recognize reality.”

McCain knows that, whether or not the talks actually end, there is never a political penalty for claiming that an international crisis is the result of Democrats not showing sufficient strength—a proposition that can never be falsified. Still, you have to wonder if McCain is right to ask if Kerry and his President have the will to follow through, by which I mean in the only way that can succeed: by offering an American plan for Israeli-Palestinian peace and rallying the world to it, while challenging, or even shattering, Netanyahu’s fragile coalition.

Kerry has “gone as far as he can as mediator,” a senior American official said last week. Precisely. The question is whether he’ll move the parties to something like binding arbitration, stop speaking about psychological breakthrough, and start implementing American policy—more Dr. Kissinger, less Dr. Phil.

The breakdown Kerry described, after all, is not in actual negotiations but in a contrived show of reciprocity that masks how negotiations are going nowhere. The most serious obstacle is Israeli and ideological. Most of Netanyahu’s Likud, along with his ultra-rightist, Orthodox coalition partners, believe that Jerusalem and the whole land of Israel is the sacred patrimony of their Jewish state. They aren’t moved by Kerry’s claim that endless rule over Palestinian Arabs will undermine Israel’s democracy. They also believe, but won’t just say, that the Palestinians’ eventual state will be across the Jordan, when Palestinians in Amman finally topple the Hashemite king and West Bankers, beginning with the élites, join them. Anyway, most think democracy is overrated. More than a quarter of Israelis tell pollsters they would like to see Yitzhak Rabin’s assassin, Yigal Amir, pardoned.

This doesn’t mean that Israelis and Palestinians could never come to terms. Twice during the past twenty years, when Netanyahu’s Likud was out of power, Abbas conducted direct negotiations with Israeli leaders: first with Labor’s Justice Minister, Yossi Beilin, in 1995, and then with centrist Prime Minister Ehud Olmert, in 2008. Twice, Abbas endorsed principles of action on the core issues proposed by Israeli interlocutors—principles he’s reaffirmed in various interviews with Israeli media during the past twelve months.

As both Abbas and Olmert told me in separate interviews for the New York Times Magazine in 2011, the outline would include a non-militarized Palestinian state in the Jordan Valley, with American security guarantees for Israel; borders based on the 1967 lines, with land swaps to allow a majority of Jewish settlers to remain in place; two capitals in Jerusalem, sharing a common municipal administration; the Holy Basin under an international custodian; and a finesse of the Palestinian “right of return” through common endorsement of the Arab Peace Initiative of 2002, and through an international commission that compensates post-1948 refugees on both sides while allowing a token few thousand Palestinian Arabs back into Israel proper.

All of these principles are anathema to the Israeli right and their friends in America. However cordial his personal relations with Netanyahu, Kerry must have known that he never had a chance to persuade this government to give up on Greater Israel any more than his boss had the chance to win the House over to a steep increase in income taxes. Settlement construction is not just an obstacle to negotiations; it gestures toward a maximal, neo-Zionist vision. If Kerry was not prepared to confront that vision and to help marginalize its advocates, he should not have undertaken this diplomacy in the first place.

The point is, the principles of a deal between moderate Palestinians and moderate Israelis are known. They are consistent with American policy since 1967. If packaged as an American plan, they’d likely gain the support of the European Union and the United Nations Security Council. All Kerry has to do—not a small thing—is embrace them and call them his own, much as President Obama haltingly did in 2011, when he argued for “the 1967 lines with mutually agreed swaps.” This is more or less what a bipartisan group of former foreign-policy advisers, including Zbigniew Brzezinski, Frank Carlucci, and Thomas Pickering, argued in Politico Magazine this week. If America had a foreign policy, and not (as George Kennan once lamented) just domestic politics, this plan might have been announced long ago.

The reality Kerry has to recognize is that his main chance at success now is to organize international consensus around a plan that he can call his own. The Oslo Agreements negotiator Dr. Ron Pundak (who, sadly, passed away Friday) suggested to me that the substance of such a plan would be something equivalent to U.N. Resolution 242 in the nineteen-seventies. As such, it would inflame the advocates for Greater Israel, who would defy it from the Hebron Hills to Fox News. But it would mobilize advocates for Global Israel, whom I’ve described here in the past: entrepreneurs, professionals, military officials, and scholars who fear terror and the surrender of the West Bank intelligence assets they assume keep it at bay, but who fear international isolation more immediately. They understand that Israel’s economy is part of a global network and that you can antagonize the globe only so far.

A Kerry Plan, moreover, would almost certainly precipitate a new election in Israel, which is the only hope for peace. Centrists like Finance Minister Yair Lapid and Justice Minister Tzipi Livni control twenty-five seats in Netanyahu’s coalition; they would not likely stay with him to fight an open-ended political battle against Kerry—not if the Obama Administration stands with him. (The President may still be afraid to gain Jewish backers in Israel if it would mean losing some in America.)

Notionally, Netanyahu could cling to power by appealing to the Mizrahi Shas and other ultra-Orthodox parties to join him in defending exclusive Jewish control of Jerusalem. But his government has enraged those very parties by cutting them out and passing legislation to draft yeshiva students. Having just sixty-one out of a hundred and twenty seats puts Netanyahu on borrowed time. If the election is fought over a Kerry Plan, Netanyahu is not likely to win—not, at least, as leader of the Likud in its current configuration. The right is not toothless, but it is fragmented, and potentially in disarray.