Having dealt with the Israelis for the better part of 40 years, I have learned never to dismiss or trivialize their foundational fears. As both former prime minister Yitzhak Rabin and current premier Binyamin Netanyahu reminded me on different occasions, Israelis don't live in some leafy Washington suburb, but in a much tougher neighborhood.

And today, it is impossible to overstate the angst, even hysteria, that Israelis are feeling about their neighborhood as they watch what is unfolding in the streets of Cairo.

Israel prides itself on being the Middle East's only true democracy, so most Israelis may be loath to admit their fear of self-government spreading to Egypt, their most important Arab ally. But by their calculation, freedom in Egypt is bound to morph into venomous anti-Israeli attitudes and actions.

Among Israel's most dire fears: Would a new Egyptian government be taken over by radical Islamists? Would it break the peace treaty between the two nations? Would it seek to go to war again? All Israeli prime ministers since the treaty was signed in 1979 have carried such fears in the back of their minds, yet they gambled that in giving up the Sinai Peninsula, the country had exchanged territory for time, perhaps in the hope that a different relationship with Egypt and their other Arab neighbors would emerge.

It's hard to imagine any of these fears materializing. Egypt's new leaders, whoever they are, will be beset by huge internal challenges, none of which could be diverted by confronting Israel. The new Egypt will need billions of dollars from the United States and much help from the international community. And violating the treaty and threatening war with Israel would be the last thing the Egyptian military needs during the uncertain transition after President Hosni Mubarak's departure.

But there's no doubt that a new Egyptian government and president, more responsive to public opinion - indeed, legitimized by the public in free elections - will be, by necessity or inclination, far more critical of Israeli actions and policies and far less likely to give Israel the benefit of any doubts. Will the new Egyptian leadership monitor smuggling across the Egypt-Gaza border as carefully? Will it be more supportive of Hamas and less understanding of Israeli concerns about Hamas's acquisition of rockets and missiles? And how will a newly elected Egyptian president interact with an Israeli prime minister? (Mubarak met regularly with Netanyahu; it's hard to imagine a new Egyptian leader doing so without demanding concessions for Palestinians or progress in the peace negotiations.)

Take a tour of the neighborhood through Israeli eyes, and you'll understand why such worries have taken on new urgency. To the north in Lebanon, Hezbollah is now the dominant political force, reequipped with thousands of rockets and backed by Syria and Iran. To the east there's Jordan, with which Israel also has a peace treaty and whose government was just changed after protests sparked by the revolts in Tunisia and Egypt. In the West Bank and Gaza, there's the Palestinian national movement, which thanks to the Hamas-Fatah split is a veritable Noah's Ark with two of everything - prime ministers, security services, constitutions and governments. And then there's Iran, whose determination to acquire nuclear weapons may force Israel one day to live under the shadow of an Islamic bomb.

Israel, nuclear weapons or not, and despite its shortsighted and harmful settlement policies, must be understood as a remarkable country living on the knife's edge. The old adage that Israelis fight the Arabs during the day and win but fight the Nazis at night and lose may be dated, but it still reflects fundamental and enduring security concerns as well as the dark side of Jewish history - both of which make Israelis worry for a living.

The inevitable hardening of Egyptian attitudes will not just constitute an Israeli problem but will pose significant concerns for Israel's major ally: the United States. The old devil's bargain in which Washington relied on Cairo for support in its war and peacemaking policies, in exchange for giving Egypt a pass on how it is governed, is probably dead. And perhaps it's just as well. The Egyptian people deserve better, and that deal didn't produce a peaceful, stable and secure Middle East, anyway - just look around.

For Egyptians, who hunger for freedom and better governance, democracy will probably secure a brighter future. For America, Egyptian democracy, however welcome in principle, will significantly narrow the political space in which U.S. administrations operate in the region. On any number of fronts, a more representative Egypt will be far less forgiving and supportive of Washington. On U.S. efforts to contain Iran, on the Middle East peace process, on the battle against terrorism and Islamic radicalism - especially if Egypt's own Islamists are part of the new governing structure - there is a great deal of uncertainty about how much cooperation we can expect.

The irony is that the challenges a new Egypt will pose to America and Israel won't come from the worst-case scenarios imagined by frantic policymakers and intelligence analysts - an extremist Muslim takeover, an abrogation of peace treaties, the closing of the Suez Canal - but from the very values of participatory government and free speech that free societies so cherish. In a more open Egypt, diverse voices reflecting Islamist currents and secular nationalists will be louder. And by definition, these voices will be more critical of America and Israel.

Events in Egypt represent not just the end of the Mubarak regime but a point of departure in Arab politics. In Tunisia and Egypt, the brush was dry and ready to burn because of deep-seated, long-held grievances - and it's hard to imagine that more sparks won't fly. Every Arab state is unique, but in many, two common conflicts persist: an economic division between the haves and the have-nots, and a political divide between the cans and the cannots - those who participate meaningfully in shaping their political systems and those who are excluded. It's hard to predict what will happen next, but change is more likely in places like Jordan, Libya and Algeria, where vulnerabilities abound, than in the Persian Gulf region, where ruling families can use cradle-to-grave benefits to co-opt opponents and preempt change.

I'd like to believe that democratic change will be peaceful, orderly and evolutionary - not hot, mean and revolutionary. But the region, penetrated for years by foreign powers and dominated by corrupt authoritarian governments, is teeming with pent-up humiliation, frustration and rage. And we can never underestimate the repressive capabilities of authoritarian regimes that tighten their grips even as power slips from their hands. The Mubarak regime's campaign to send its agents to provoke violence and to kill, wound and intimidate the opposition and the news media reflects only a fraction of its latent power. And the Syrian reaction to domestic unrest might be far worse.

In the middle of all this turmoil sits the United States, unable to extricate itself from the region yet probably unable to fix these problems or alter its policies, along with Israel, which looks at the possible transformation of the Middle East not as an opportunity but as a moment replete with risks. (In this environment, to believe, as some analysts have argued, that any Israeli government would negotiate a conflict-ending agreement with the Palestinians to preempt further radicalization in the region is to believe in the peace-process tooth fairy.)

Without Egypt, there can be neither peace nor war, and for 30 years Israelis had the first and avoided the second. Peace with Jordan, the neutralization of Iraq and the U.S.-Israeli relationship all left the Israelis - despite their constant worries - fairly confident that they could deal with any threats to their security. But now, with Egyptian politics in turmoil, Iran emerging as a potential nuclear threat and the prospect of trouble in Jordan and elsewhere, they're not so sure. That Mubarak is falling not by an assassin's hand but because of a young generation of tweeters is hardly consolation. This is one pharaoh that Israelis wish had stayed on the throne.

aaron.miller@wilsoncenter.org

Aaron David Miller has advised several U.S. secretaries of state on the Middle East peace process and is the author of the forthcoming "Can America Have Another Great President?" He is a public policy scholar at the Woodrow Wilson International Center for Scholars and will be online at 12 ET on Monday, Feb. 7 to chat. Submit your questions and comments before or during the discussion.

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