American presidents have, with rare exception, spoken of Israel with biblical reverence.
If anything, the language has only gotten more pro-Israel with each successive White House administration since Harry Truman made the United States the first country to recognize Israel's independence in 1948.
Barack Obama has torn up the old script. If the policies of his administration toward Israel represent incremental change more than a break with the past, he talks about them in ways no previous president dared.
Mr. Obama's public endorsement of Israel's pre-1967 borders as the basis for a peace deal with the Palestinians has sparked outrage in Israel, on the U.S. right and from the powerful American Jewish lobby.
Just why Mr. Obama has chosen this tack, and why he has done so now, speaks both to the unprecedented change sweeping the Arab world and the 44th president's desire to ensure the United States does not squander a chance to reset U.S.-Arab relations by showing favouritism toward Israel.
It also reflects Mr. Obama's recognition that the elusive goal of Middle East peace has not been advanced by treating Israel with kid gloves. That has only put the United States on the outs with most of the Arab world.
But there are also big risks in Mr. Obama's approach. Domestically, it is largely at odds with American public opinion and the unshakeable solidarity toward Israel expressed by the Tea Party movement and Christian right. Both are likely to be major forces in the 2012 election.
And given Mr. Obama's already chilly relationship with Israeli Prime Minister Benjamin Netanyahu, the President's forthrightness may only lead to a hardening of positions on all sides.
"A peace based on illusions will crash eventually on the rocks of the Middle Eastern reality," Mr. Netanyahu said in the Oval Office Friday as Mr. Obama looked on uncomfortably. "While Israel is prepared to make generous compromises for peace, it cannot go back to the 1967 lines because these lines are indefensible."
On Thursday, Mr. Obama broke with the public pronouncements of his predecessors by explicitly calling for peace negotiations based on the borders of Israel that existed before the 1967 Six-Day War, the conflict that led to Israeli occupation of the West Bank and Gaza Strip.
Mr. Obama qualified his statement by referring to the "1967 lines with mutually agreed swaps." It was an implicit reference to Jewish settlements in the West Bank and East Jerusalem, territories that Israel might keep in exchange for ceding other land to the Palestinians. (Israel pulled out of Gaza in 2005.)
But the nuances were largely overshadowed by Mr. Obama's unprecedented language, as the President must have known they would be.
"The phrase in Obama's speech is not logically contradictory to earlier statements [by U.S. presidents]but it does push as far as possible toward the current position of much of the Palestinian leadership," George Washington University political science professor Nathan Brown explained. "The [George W.]Bush administration had pushed in the opposite direction, which explains in part the very angry official Israeli reaction."
In Ottawa, the Harper government refused to publicly endorse Mr. Obama's starting point for Middle East peace talks. A federal official, who spoke on the condition of anonymity, insisted that outsiders cannot dictate the basis for negotiations.
"If the two parties are of the view that this is a starting point, that is fine for them," the senior federal official said. "If it's border, if it's other issues, it has to be negotiated, it cannot be unilateral action."
In many ways, Mr. Obama's much-anticipated Middle East speech - broadcast live from the State Department on Thursday and directed as much at an Arab audience as an American one - underscored the similarities between his current foreign policy and that of Mr. Bush.
"The United States was founded on the belief that people should govern themselves," Mr. Obama said, in what many analysts considered an unsubtle echo of Mr. Bush's so-called ideals-driven Freedom Agenda. "And, now, we cannot hesitate to stand squarely on the side of those who are reaching for their rights."