Soothing words from Washington at the weekend, aimed at placating Afghanistan's president Hamid Karzai after last week's public falling out, follow a familiar pattern. The White House was livid with Gordon Brown over last year's release to Libya of the Lockerbie bomber. But things were patched up once tempers cooled.

Now James Jones, Barack Obama's national security adviser, is claiming US relations with Israel are "fine" despite the furious row over prime minister Binyamin Netanyahu's refusal to halt Jewish settlement expansion in east Jerusalem, as demanded by Obama. Secretary of state Hillary Clinton was similarly conciliatory at the weekend, extolling the virtues of "strategic patience".

But relations are anything but fine, if the truth were told. The Obama team knows it cannot allow the present impasse to persist indefinitely, with Israel and the Palestinians declining even to begin the "proximity talks" to which both are committed. Jordan's King Abdullah sounded a grim warning last week about growing hostility towards Israel among so-called moderate Arabs. His message to Obama: do something, and do it soon, or you will regret it.

Obama may hear similar calls from Egypt, Saudi Arabia and other regional countries attending this week's nuclear summit in Washington (which Netanyahu has boycotted). Meanwhile, the imposition by the Israeli army of tougher residency rules in the occupied West Bank that rights groups say could allow the deportation of thousands of Palestinians represents another nasty surprise for Washington from Netanyahu's recalcitrant government.

Does Obama have a plan? Not yet, but one appears to be in the works. Reports speak of a possible new US demarche in which Obama would table a grand peace initiative, multilateral in approach and embracing all the parties to the Arab-Israeli conflict, not just Palestinians and Jews. The proposal would be a composite of the 2000 Camp David blueprint, which so nearly took hold, and the 2002 Arab peace plan, plus various subsequent refinements.

Such an initiative was discussed by Obama, Jones and six former national security advisers at a recent White House meeting. According to Washington Post columnist David Ignatius, Brent Scowcroft, who advised George Bush Snr, led the charge for a bold new opening, backed by Colin Powell, Frank Carlucci and Sandy Berger. Their argument was that the "incrementalist", step-by-step approach favoured by Obama's chief envoy, George Mitchell, has failed. Even if proximity talks got off the ground, they would quickly stall, they said. Thus a sort of grand-slam deal, before the end of Obama's first term, was the way to go.

The basics are already in place (though far from agreed): compensation for displaced Palestinians instead of a right of return; the sharing of Jerusalem, with a special dispensation for the Old City's holy sites; Israel's withdrawal to the pre-1967 borders, with some territorial adjustment and swaps; international security guarantees encompassing in particular the Jordan valley; and Arab recognition of Israel.

Zbigniew Brzezinski, Jimmy Carter's national security adviser, has since stepped up the pace, urging Obama to make an Anwar Sadat-style "journey for peace" by conducting Arab and peace-process leaders in joint appearances at the Knesset (Israel's parliament) and the Palestinian legislature in Ramallah. "Only a bold and dramatic gesture in a historically significant setting can generate the political and psychological momentum needed for a major breakthrough," he said.

Although Jones emphasises that nothing is yet decided, pressure on Obama to make a move is mounting. The Palestinians would applaud more direct US "ownership" of a rebooted peace process; the Arabs might see it as an endorsement of their position; and as Seth Freedman argues on Cif today, Israelis would welcome the economic boom that would follow a settlement.

And then, conversely, there's the certainty that if the peace process definitively dies, extremists on both sides will try to fill the vacuum. Recent clashes in Gaza should be seen as a red alarm: renewed fighting suits those who oppose a compromise peace.

White House officials see another big upside: ending the Arab-Israeli standoff would make it much easier to present a united front to Iran. It might also reduce anti-American sentiment in the Muslim world and thus assist US policy aims in Afghanistan, Iraq and in the "war on terror" – although foreign policy specialists such as Ray Takeyh are sceptical that Arab governments will ever agree to confront Tehran, even if peace reigns throughout the region.

As Obama ponders his next move, the big question is how Israel's rightwing leadership, and its American supporters, would react to any US effort to prescribe or impose the broad terms of a settlement – and what to do if Netanyahu refused to go along. Such a collision, potentially fracturing the US-Israel relationship, could make the row over east Jerusalem look like a minor spat. And the biggest beneficiary would be both countries' biggest antagonist – Iran.