A sharp deterioration in Egypt's relations with Israel is further complicating Washington's faltering efforts to move the Middle East peace process forward.

The U.S. has long relied on Egypt's key role as a mediator in the region, most crucially in trying to reconcile rival Palestinian factions. But those efforts are now stalled as U.S. Secretary of State Hillary Clinton rushes to Cairo Wednesday to meet Egyptian President Hosni Mubarak, a clear sign of concern that Egyptian and Arab support for the peace efforts may be waning.

Clinton, who extended her Mideast trip by a day to come to Cairo, arrives at one of the lowest ebbs in three decades of Egyptian-Israeli peace. Over the past month, Egypt has been scaling back its already limited contacts with Israel in an apparent protest over Israel's refusal to halt Jewish settlement in the West Bank and east Jerusalem.

Egypt has tried to keep Israelis away from several international forums and censured an academic for meeting Israel's ambassador to Cairo. Egyptians have also bitterly blamed Israel for their culture minister's loss of the top post at the U.N. culture agency, UNESCO, and even for attempts by African countries to grab a bigger share of the Nile's waters.

"If generally they have been cool, now their ties seem to be frosty," said Samir Ghattas, head of the Cairo-based Maqdus Center for Strategic Studies.

Egypt first to make peace
Israel acknowledged the Egyptian frictions but tried to play them down, contending the hard line against the Jewish state comes more from the society than from Egypt's government.

Egypt was the first Arab country to make peace with Israel in 1979 and though ties have never been warm, it has played a critical role as Mideast peace mediator. The Egyptians helped end the Gaza war early this year. More recently, Egyptian and German mediators brokered a deal between Israel and Hamas to exchange 19 Palestinian women prisoners for the first video images of Israeli soldier Gilled Shallot since he was captured in Gaza in 2006.