Associated Press
Israeli soldiers with armored vehicles gather in a staging ground near the border with Gaza Strip, southern Israel, Friday, Nov. 16, 2012. Fierce clashes between Israeli forces and Gaza militants are continuing for the third day.

One of the great lasting achievements for peace in the past 30 years has been the treaty between Israel and Egypt, brokered by Israeli Prime Minister Menachem Begin and Egyptian President Anwar Sadat with the guidance and encouragement of U.S. President Jimmy Carter in 1979. That important pillar of peace appears threatened as Israel responds to escalated security threats from the militant Islamic group Hamas in Gaza.

While the American public has been understandably preoccupied with elections, natural disasters and public finances, southern Israel has patiently borne random missile attacks from Hamas in Gaza — more than 800 documented missile attacks in the past year alone.

Last week, Israeli forces responded by assassinating Hamas military leader Ahmed Jabari, the unapologetic leader of this indiscriminate terror on Israel. Israeli retaliation was met with Palestinian retaliation and, at the time we went to press, Israel and Gaza appeared to be on the brink of a significant military conflict not unlike the three-week war in 2008-2009 when Israeli troops invaded Gaza and degraded the military capacity of Hamas.

But since 2009 much has changed in the region, making these seeming tactical military maneuvers strategically consequential for peace throughout the Middle East.

Most notable is the change in Egypt. In 2009, then-Egyptian President Hosni Mubarak stood by while Israel invaded Gaza, much to the consternation of ordinary Egyptians.

But the intervening Egyptian Revolution has transformed the Egyptian presidency from an autocratic American ally who knew his military might depended on keeping peace with Israel, to a popularly elected Islamist whose political power comes from popular sentiment in an increasingly radicalized Egypt.

Even before this current conflict in Gaza, Egyptian President Mohammed Morsi has been chilly to Egypt's already cold peace with Israel, refusing to ever use the name Israel in any public statement, turning a blind eye to the Salafist radicalization happening in the Sinai and possibly violating terms of the 1979 treaty through military maneuvers in the supposedly demilitarized Sinai.

Now with the latest open hostilities between Israel and Gaza, Morsi has withdrawn the Egyptian ambassador to Israel and dispatched his prime minister to Gaza to show solidarity with Hamas.

The erosion of Egypt's commitment to peace with Israel is deeply disturbing. It adds tremendous uncertainty and instability in a region already racked by radicalization and destabilization from the civil war to Israel's north in Syria.

With Hamas missiles now reaching Tel Aviv and Jerusalem, the United States government must exert full diplomatic pressure on Egypt to maintain its peace with Israel. Morsi must understand that all direct aid, as well as billions of dollars of IMF loans are at risk should Egypt try to interfere militarily into Israel's efforts to defend itself against Hamas.