Of all the world's statesmen, the one closest to Prime Minister Benjamin Netanyahu is Egyptian President Hosni Mubarak. They have met four times since Netanyahu returned to power, and unlike U.S. President Barack Obama, Mubarak has no qualms about shaking Netanyahu's hand in public. "Ties are much closer than they seem," said a highly placed Israeli source. Referring to the peace process, an Obama administration official said "Mubarak tells people he is sure Netanyahu will do the right thing."

The wonderful friendship stems from the leaders' shared concerns about Iran. Netanyahu is anxious about that country's nuclear program, while Mubarak fears the Islamic Republic's potential to undermine his own regime. Israel and Egypt cooperate to enforce the closure of the Gaza Strip, in order to reduce weapons smuggling and weaken the Hamas government there.

This collaboration cannot be taken for granted. Mubarak had dismal relations with previous Likud prime ministers, from Menachem Begin to Ariel Sharon, and Netanyahu's cabinet includes powerful ministers who have vigorously condemned Mubarak in the past. Foreign Minister Avigdor Lieberman berated the rais (leader ) for refusing to visit Israel, and Finance Minister Yuval Steinitz issued a stern warning over what he called the "Egyptian threat." Now, however, they are keeping quiet. This testy cabinet, which scuffled with Turkey over a television program and with Sweden over a newspaper article, is taking Egypt's honor seriously, turning a blind eye to the hostile Egyptian press and even to Cairo's diplomatic campaign against Israel's nuclear program.

Israel is conceding a valuable public-relations card, refraining from calling out Egypt over its own responsibility for the dire situation in Gaza. Netanyahu is willing to absorb international censure over the "siege," keeping mum over the fact that Gaza shares a border with Egypt and that that country too could take better care of the unfortunate Palestinians. He knows that any such remarks would stir Cairo's wrath, and would rather see Israel castigated abroad than irk Mubarak.

The Israel-Egypt peace treaty was signed several weeks after the fall of the Shah of Iran, and since then Cairo has replaced Tehran as Israel's regional ally and energy supplier. The peace agreement enabled Israel to cut its defense budget, obviating the need for a large, costly security force in the Negev. Time and again, the treaty has stood the test of wars and intifadas raging on Israel's other fronts.

Mubarak, Egypt's longest-serving leader since Mohammad Ali, in the 19th century, is responsible for this stability. But at 82, his time is running out, and there is no clear successor. Were Israel's leaders given one wish, they might ask that Mubarak be granted immortality. "Let him stay with us," says the Israeli source.

Discussing Mubarak's successor remains taboo in Israel. But no great imagination is required to understand that after 40 years of quiet on our southern border, Israelis dread "the Iranian scenario" - the rise of an Islamic regime in the world's largest Arab state, just over the border and armed with advanced U.S. weapons. The danger posed by Tehran looks like an innocent joke compared to a hostile Egypt run by the Muslim Brotherhood.

Adam Shatz, a journalist who is a fierce critic of Israel, published an article in the current issue of London Review of Books in which he compared the political environment in Egypt today with that of the twilight of the Shah's rule in Iran, 30 years ago. Israeli experts disagree. Egypt's intelligence and security services wield a tight grip on the country, they argue, and they, together with the army, will pick the next leader. None of these experts is willing to say whether it will be Mubarak's son, Gamal; intelligence chief Omar Suleiman, or perhaps some anonymous army general.

By all appearances, Obama won't repeat the mistakes of Jimmy Carter, who encouraged the fall of the Shah over the issue of human rights. Obama understands that Egypt is the West's most important bulwark against Iran's rising influence, and is taking steps to bolster the current regime rather than fantasizing about democratization. Netanyahu can only hope that Obama continues this policy. In the meantime, he may wish his dear friend the rais many more healthy years.