jerusalem  |  Last week’s multifront Palestinian terrorist attack along the Egyptian-Israeli border highlighted two major new challenges to Israel’s national security.

First is the breakdown of Egyptian central authority in the Sinai Peninsula, which has created fertile ground for terrorism against Israel. Complicating matters further is a heightened sensitivity in post-Mubarak Egypt to Israeli retaliation, especially if it entails action in territory nominally controlled by Egypt.

If not carefully managed, Israeli analysts say, the twin challenges could bring the Israeli-Egyptian peace treaty, a cornerstone of regional stability for over three decades, into question.

A protester’s sign expresses his feelings near the Israeli Embassy in Cairo on Aug. 21.

In separate interviews on Israel Radio, former generals Giora Eiland and Yisrael Ziv argued that the top priority for Israel is to prevent any erosion in the peace with Egypt. Nahum Barnea, senior political analyst for Israel’s daily Yediot Achronot, expanded on the theme.

“What is at stake,” Barnea wrote Aug. 22, is “how can Israel help the new Egyptian regime fend off the street pressure to cancel the peace treaty with Israel?”

Ever since former Egyptian president Hosni Mubarak’s ouster in February, the Sinai has been in a state of virtual anarchy. Any semblance of order that existed under Mubarak has been eroded. Scores of terrorists from Gaza and farther afield have been able to move in the area with impunity.

Arms smuggling through the Sinai to Gaza — always a problem — has reached unprecedented levels. The pipeline carrying Egyptian natural gas to Israel has been sabotaged five times since February.

In order to enable the Egyptians to reassert their control, Israeli officials indicate they may be willing to consider an amendment to the Egyptian-Israeli peace accords to allow a stronger Egyptian military presence in Sinai, close to the border with Israel and in the key area along the border with Gaza.

A week before the Aug. 18 terrorist attack that killed eight Israelis, Israel agreed to the deployment of an additional 1,000 Egyptian troops in the sensitive area, despite treaty limitations that allow for only a few hundred lightly armed policemen to ensure that the Sinai does not become a staging ground for assaults against Israel.

Israeli military analysts say much will depend on the degree to which the Egyptian forces are willing to take on the smugglers and the terrorists.

Until now, soldiers in the Sinai or lightly armed policemen closer to the border have been taking kickbacks to look the other way. Without a change in attitude, simply beefing up Egyptian forces will not solve the problem, Israeli analysts say. Indeed, they say, some of the Gaza terrorists who fired on Israeli vehicles last week operated unhindered close to an Egyptian military position.

Even more worrying for Israel than the danger of having terrorists roaming freely around the Sinai is the potential threat the new situation poses to the peace with Egypt.

In the Aug. 18 exchanges of fire with the terrorists, three Egyptian border policemen were killed. The incident sparked angry demonstrations outside the Israeli Embassy in Cairo.

What makes this particularly troubling for Israel is that in the new Egypt, a product of the Arab Spring that has given greater weight to the voice of the people, the country’s new leaders will have to take the widespread popular animosity toward Israel into account.

This, the analysts say, could bring the peace treaty with Israel under review.

Still, for all the public debate on the issue in Egypt, most experts do not anticipate a new government abrogating the peace treaty with Israel in the near future.

They point out that the two countries still share common interests — for example, a quiet Sinai, in which forces like al Qaida, which also threaten Egypt, are neutralized. More important, the Egyptians know that if they cancel the peace treaty with Israel, they will forfeit the huge economic and military aid package they have been receiving from the United States since 1979, when the treaty was signed under American auspices.

At one point during the current crisis, when the Egyptians appeared to threaten to recall their ambassador from Tel Aviv, the United States reportedly warned that if they went ahead, some of the aid would be withheld. The Egyptians quickly dialed down the rhetoric. On Aug. 22, the Egyptian foreign minister, Mohammed Kamel Amr, denied that a recall was ever on the table.

Yoram Meital, a leading Israeli expert on Egypt at Ben-Gurion University, says the changes in Egypt have significantly altered the military equation between Israel and the Gaza militants.

For one thing, Palestinian action from Sinai puts Israel in a very tricky position, because if Israel hits back hard on Egyptian territory, it risks escalation with Egypt. Secondly, should Israel undertake a major military operation in Gaza, it is likely to encounter much firmer Egyptian censure than it did in Mubarak’s day, given the predominant anti-Israel sentiment in today’s Egypt.

Leaders of the Israel Defense Forces are thinking deeply about this. Over time, military planners say, Israel cannot afford to allow Gaza militants to use the Sinai as a launching pad for operations against Israel — precisely because it could lead to conflict with Egypt. At some point, they say, Israel will have deal with the Palestinian terrorist infrastructure in Gaza itself and not in Sinai, to minimize the risk of a confrontation with Egypt.