Israel's so-called cold peace with Egypt is looking colder by the day.

Early Tuesday, Egypt reportedly permitted two Iranian warships to enter the Suez Canal for the first time since the Iranian Revolution in 1979.

During a mass prayer service Friday in Cairo's Tahrir Square, anti-Israel cleric Yusuf Qaradawi— who returned to Egypt after years in exile — called for the "conquest" of Jerusalem's Al Aqsa mosque, Islam's third-holiest site, which was captured by Israel in the 1967 Middle East War and sits atop a Jewish holy site.

As well, natural gas shipments to Israel, Jordan and Syria remain suspended after unknown assailants this month tried to bomb the pipeline route in the Sinai peninsula. An organizer of the protests that toppled Egyptian President Hosni Mubarak said last week that his group opposed resumption of exports to the "Zionist entity."

Though Israelis have taken comfort in assurances from Egypt's military that international agreements such as the 1979 Egyptian-Israeli peace treaty will be honored during its interim control of the country, opposition leaders in Egypt are talking about the need to "reassess" or "revise" the landmark pact.

Some Israelis fear they are already seeing signs of an anti-Israel backlash stemming from decades of pent-up hostility on the streets of Egypt, where many still view Israel as an enemy.

"One must bear in mind that many of the young Egyptians who took to the streets demanding democracy and prosperity are anti-American and anti-Israel," said Michael Laskier, Mideast studies professor at Bar-Ilan University. "They may decide to settle a score with the two."

Even if Egypt's next government opts to maintain the peace treaty, many Israelis are worried that a future democratic Egypt could follow the path of Turkey, a onetime Israeli ally with whom relations have soured over the last year.

"Egypt is signaling that it is no longer committed to its strategic alliance with Israel against Iran, and that Cairo is now willing to do business with Tehran," Israeli columnist Aluf Benn wrote in the newspaper Haaretz on Sunday, reacting to an announcement about the Iranian warships. "This is precisely what Turkey has done in recent years under Prime Minister Recep Tayyip Erdogan."

Though the peace treaty requires Egypt to provide Israel with passage through the canal and make efforts to prevent hostile elements from attacking Israel from inside Egypt's borders, other forms of cooperation are not formally part of the agreement.

In addition to terminating natural gas exports, which accounted for about 40% of Israel's supply, a future Egyptian government might halt its assistance in stemming the flood of African immigrants through Egypt into Israel or weapons into the Gaza Strip, without violating the terms of the treaty, analysts say.

"Undoing the peace treaty entirely risks losing significant American aid," Laskier said. "So a new regime could do everything to avoid angering the Obama administration by not really breaking the peace, but not keeping it, either. The peace treaty could be weakened and emptied of [meaning]."

The passage of Iran's naval vessels, which are reportedly heading to Syria, is another example of how a shift in Egypt's policies could affect Israel's security without violating the treaty, experts said. The Reuters news agency said two Iranian warships, a frigate and a supply ship, entered the canal early Tuesday morning.

Israeli Prime Minister Benjamin Netanyahu has so far directed his anger largely toward Iran, saying during a Cabinet meeting Sunday that Iran was "trying to take advantage of the situation that has arisen and broaden its influence."

Because the Iranian ships are reportedly not ferrying weapons, Egyptian officials have said they are unable to justify blocking them.

In 2009, the tables were turned when Israeli military vessels were permitted through the canal to the Red Sea in what was widely seen as a message to Iran about Israel's ability to strike. Israelis have said they view Iran's nuclear program as a threat to their existence and have refused to rule out an airstrike — similar to ones Israel launched against Iraq in 1981 and Syria in 2007.

By dispatching its ships to the Mediterranean, Iran is sending a message to Israel, said Yoel Guzansky, a research fellow at the Institute for National Security Studies in Tel Aviv. "While the passage of the ships is not of extraordinary security consequence, it conveys a message to Israel," he said. "Egypt was the keystone in efforts to block Iran. I do not know if Iran would have dared to attempt this move with Mubarak in his prime."

Some Israeli commentators have argued that without Mubarak's help in organizing an Arab alliance against Iran, Israel's ability to launch a military strike on that country is diminished.

"When someone in Israel is debating whether to strike, it will be taken into consideration how Arab states, especially Egypt, will react," said Ilan Mizrahi, former head of Israel's National Security Council.