WASHINGTON -- The demonstrations against President Hosni Mubarak's government in Egypt are rocking the relationship between the United States and its most important Arab ally. But they are also rocking an even more fundamental relationship for the United States -- its 60-year alliance with Israel.
Obama administration officials have been on the telephone almost daily with their Israeli counterparts urging them to ''please chill out,'' in the words of one senior administration official, as President Obama has raced to respond to the rapidly unfolding events.
But the crisis raises many questions about how the United States will navigate its relationship with Israel -- in particular the balance between encouraging the development of a democratic government in Egypt and the desire in Washington not to risk a new government's abandoning Mr. Mubarak's benign posture toward Israel.
The unsettled outlook in Egypt has also scrambled American calculations about nurturing peace talks back to life between Israel and the Palestinians. And it has left both American and Israeli diplomats wondering about a broader regional realignment in which Israel would be left feeling more isolated and its enemies, including Iran and Syria, emboldened.
Israeli government officials started out urging the Obama administration to back Mr. Mubarak, administration officials said, and were initially angry at Mr. Obama for publicly calling on the Egyptian leader to agree to a transition.
''The Israelis are saying, apres Mubarak, le deluge,'' said Daniel Levy, a former Israeli peace negotiator. And that, in turn, Mr. Levy said, ''gets to the core of what is the American interest in this. It's Israel. It's not worry about whether the Egyptians are going to close down the Suez Canal, or even the narrower terror issue. It really can be distilled down to one thing, and that's Israel.''
Obama officials say that the United States cannot rule out the possibility of engagement with the Muslim Brotherhood -- the largest opposition group in Egypt -- at the same time that it is espousing support for a democratic Egypt. If Egyptians are allowed free and fair elections, a goal of the Obama administration, then, administration officials say, they will have to deal with the real possibility that an Egyptian government might include members of the Muslim Brotherhood.
American Jewish leaders have also been voicing uneasiness about Mohamed ElBaradei, the former head of the atomic energy agency who is also part of the opposition to Mr. Mubarak.
Malcolm I. Hoenlein, the executive vice president of the Conference of Presidents of Major American Jewish Organizations, an umbrella group, said that in his work as a nuclear watchdog, Mr. ElBaradei covered up Iran's nuclear weapons capability in the reports issued by his agency.
''He is a stooge of Iran, and I don't use the term lightly,'' Mr. Hoenlein said in an online interview on Sunday with Yeshiva World News. ''He fronted for them, he distorted the reports.''
But many American Jews are also debating the irony of Israel, which long promoted itself as the only democracy in its neighborhood, now voicing concerns about the birth of a democracy next door. And that that democratic movement is happening in Egypt -- with all of its historic ties to the enslavement of the Jewish people -- is being picked apart in conversations within American Jewish communities.
Mr. Levy, the former Israeli peace negotiator, said: ''The problem for America is, you can balance being the carrier for the Israeli agenda with Arab autocrats, but with Arab democracies, you can't do that.''
