In the wake of Israeli Prime Minister Benjamin Netanyahu’s decisive reelection, the Obama administration is revisiting longtime assumptions about America’s role as a shield for Israel against international pressure.

Angered by Netanyahu’s hard-line platform toward the Palestinians, top Obama officials would not rule out the possibility of a change in American posture at the United Nations, where the U.S. has historically fended off resolutions hostile to Israel.

And despite signals from Israel suggesting that Netanyahu might walk back his rejection, late in the campaign, of a Palestinian state under his watch, Obama officials say they are taking him at his word.

“The positions taken by the prime minister in the last days of the campaign have raised very significant substantive questions that go far beyond just optics,” said a senior administration official, adding that recent Israeli government actions were in keeping with Netanyahu’s rhetoric.

While saying it was “premature” to discuss Washington’s policy response, the official wouldn’t rule out a modified American posture at the United Nations, where the U.S. has long fended off resolutions criticizing Israeli settlement activity and demanding its withdrawal from Palestinian territories.

“We are signaling that if the Israeli government’s position is no longer to pursue a Palestinian state, we’re going to have to broaden the spectrum of options we pursue going forward,” the official said.

There is no virtually no chance that the U.S. will trim its financial or military support for Israel. But some analysts believe that going forward, Netanyahu may be vulnerable in international forums where the U.S. has long been a bulwark against criticism of Israel and its presence in Palestinian territories.

“I do think the administration is going to look very closely at the possibility of either joining, or at least not blocking an internationally backed move at the U.N. to restate the parameters for ending the conflict,” said Jeremy Ben-Ami, president of the left-leaning pro-Israel group J Street.

Netanyahu’s campaign statements “make it a lot easier for the administration to justify going down a more international route,” Ben-Ami added.

The chief Palestinian negotiator with Israel, Saeb Erakat, told Agence France-Press that the Palestinians will “accelerate, continue and intensify” their diplomatic efforts to pressure Israel.

The U.S. has run critical interference for Israel on such measures in the past. Last November, the U.N. Security Council considered a draft resolution, pushed by the Palestinians and Arab countries, demanding an Israeli withdrawal from the West Bank within three years. The U.S. quietly quashed the effort.

In February 2011, Obama exercised his first Security Council veto to strike down a resolution condemning Israeli settlement activity in Palestinian territory. Every other one of the Security Council’s 15 members supported the resolution.

Obama officials must now decide whether more international pressure on Israel can help bring a conservative Netanyahu-led government back to the negotiating table with the Palestinians — or whether such pressure would simply provoke a defiant reaction, as some fear.

Obama has other diplomatic options. He could expend less political capital to oppose growing momentum within the European Union to impose sanctions on Israel for its settlement activity.

More provocative to Israel would be any softening of Obama’s opposition to Palestinian efforts to join the International Criminal Court, which the Palestinian Authority will formally join on April 1. Under a law passed by Congress, any Palestinian bid to bring war crimes charges against Israel at the court will automatically sever America’s $400 million in annual aid to the Palestinian Authority, although some experts suggested Obama could find indirect ways to continue some funding — even if only to prevent a dangerous collapse of the Palestinian governing body.

On Monday, Danny Ayalon, a former Israeli ambassador to the U.S., said he expected Netanyahu to “retract” a campaign statement he made ruling out the possibility of a Palestinian state during his tenure as prime minister. But the senior Obama official said that the administration believes the prime minister meant what he said because Netanyahu made multiple comments during the closing days of his campaign as he appealed to conservative voters.

The official noted that Netanyahu also admitted that, during his first term as prime minister in the mid-1990s, he had approved construction at the Israeli settlement of Har Homa to cut off any possible linkage between Palestinian-majority areas. “It was a way of stopping Bethlehem from moving toward Jerusalem,” Netanyahu said.

“To actually come out and say that this construction is actually driven by efforts to undermine a future Palestinian state is fairly dramatic,” said the official. He added that the Obama administration is focused not just on Netanyahu’s comments but on his “several-year record of action on this issue” casting doubt on his desire for a peace agreement.

A former senior Obama official was more direct, saying of the Israeli leader: “He’s shown his true colors.”

For months, Israeli officials have insisted that the real problem lies not with their policies but with the Palestinians. They cite Palestinian Authority President Mahmoud Abbas’s formation of a unity government with the Gaza-based militant group Hamas last June, and his December move to have the Palestinian Authority join the criminal court — actions that Israel vehemently opposed.

Even before the events of recent days, pro-Israel conservatives were alarmed about the possibility of a toughened policy from the Obama White House in the wake of Secretary of State’s John Kerry’s failed push for an Israeli-Arab peace agreement. That effort collapsed last spring, and some key Obama officials primarily blamed Israel.

Since then, the Obama administration has criticized Israel’s settlement building with increasingly blunt language.

In November, after Israel’s government announced plans to build 2,500 new homes in East Jerusalem, for instance, White House spokesman Josh Earnest warned that the news would draw international scorn — pointedly adding that it would “distance Israel from even its closest allies.”

Another concern for Netanyahu allies is a recent White House staff shuffle, in which the national security director’s point man on Israel, Phil Gordon, departed and was replaced by Rob Malley, a former adviser to Bill Clinton.

Malley’s ascension to the post of White House coordinator for the Middle East, North Africa, and the Gulf Region drew outrage from some Israeli-American groups, who pointed to his past contacts, while a staffer at the nonprofit International Crisis Group, with Hamas. While the U.S. considers Hamas a terrorist organization, Malley has argued that any Israeli-Arab peace deal will require dealing with the Gaza-based group.

As a candidate in 2008, Obama ousted Malley from his campaign advisory team after critics attacked his Hamas contacts. Malley has also publicly blamed Israel for the failure of peace talks with the Palestinians.

Soon after Malley’s March 6 promotion from a more junior White House post, the Zionist Organization of America lashed out with a statement calling him“an Israel-basher, an advocate of U.S. recognition of major, unreconstructed terrorist groups Hamas and Hezbollah, and a proponent of the containment of Iran.”

But many former top Middle East policymakers with ties to both parties defend Malley as fair-minded and highly skilled. In a statement at the time of his promotion, National Security Adviser Susan Rice called Malley “one of my most trusted advisers.”