Daniel Kurtzer, the former U.S. ambassador to Israel, said on Tuesday that a government led by Benjamin Netanyahu that also included Yisrael Beiteinu chairman Avigdor Lieberman would be a "bad combination for American interests."

"It would be much more difficult for the right-wing even with determined American leadership to advance the peace process," Kurtzer said. "Not impossible, but very difficult."

The U.S. official position is that it looks forward to "working with any government," but in back-channel messages the Obama administration has made it clear it would like to see a Likud-Kadima unity government in Jerusalem over a narrow right-wing government which would in all likelihood result in a freeze in peace talks with the Palestinians.

The former envoy added that the Obama administration would find it politically risky to embrace a government that included Lieberman, who has voiced controversial views about Arabs.

"There will be an image problem for an American administration to support a government that includes a politician who was defined as racist," Kurtzer said during an appearance at Georgetown University. "But the Israeli system doesn't respond well to perceptions of outside parties," he said.

Kurtzer, who was speaking at an event examining the U.S. perspective on the Gaza conflict, said the peace process will be on hold as Israel spends the next five weeks attempting to cobble together a stable coalition.

He added that the recent Israeli operation in the Gaza Strip had tacit support from Arab regimes who are fearful of growing Iranian influence.

"Israel was in a fact an instrument, a tool of the moderate Sunni majority in the Middle East that sought to push back Shia [influence]," Kurtzer said. "There was great anger at Hamas's means of governance in Gaza. To be sure, there was as well a great split in the Arab world between the Arab street and the governing circles. About week three of the war the pressure from the street was too much even for those regimes. But it'll be interesting over time to see over time if what we saw in the first two weeks of the war to characterize Arab government behavior."

Meanwhile, two Massachusetts professors, Dennis Gaitsgory, a mathematician from Harvard University, and MIT Professor Josh Tenenbaum this week launched an online petition entitled "No government with Lieberman," calling on the next Israeli prime minister to cease courting the Yisrael Beiteinu leader.

The petition is addressed to the leaders of Kadima and Likud, the two factions with the best chance to cobble together a coalition.

"As friends of Israel and supporters of Israeli democracy, we say: Don't do it!" the petition reads. "Through his platform and his rhetoric, Mr. Lieberman threatens Israeli society with the darkness of race-baiting, demagoguery and ultra-nationalism.

"We respect the right of Israeli citizens to elect their own political leaders. Yet as supporters of a democratic state, we cannot remain silent at this crucial time."