In an attempt to end the growing anarchy in the Sinai Peninsula, Egypt began a major military operation this week to root out the Islamist terrorists who have been operating in the area.
The Egyptian operation was co-ordinated with the Israeli government, as is required by the peace accord between the two countries.
Under the treaty, Egypt is allowed to position only a limited number of security forces in Sinai. This time, however, Israel approved a much larger force which includes 2000 soldiers and armoured vehicles.
According to a senior Israeli source, "We had no trouble allowing this because the Egyptian military is fully co-ordinated with us and it is in Israel's interests that they fight the terrorist groups working in Sinai."
Following the revolution in Cairo that deposed ex-president Hosni Mubarak in February, there has been growing unrest in Sinai, with Bedouin tribes, operating with impunity near the Gaza crossing, smuggling weapons and other goods into the Palestinian side.
Attempts by the Egyptian security forces to prevent the smuggling have been rebuffed and the Israeli security establishment is concerned that arms shipments to Hamas and other Palestinian terror organisations in Gaza have intensified.
The civil war in neighbouring Libya has also contributed to the amount of military equipment in Sinai: weapons plundered from abandoned Libyan army depots have found their way into Egypt. The Israeli National Security Council has issued a number of stern warnings to Israelis not to travel into Sinai as there is a clear and present danger of attacks and kidnapping.
Another result of the worsening security situation in Sinai has been the repeated sabotage of the pipeline which pumps Egyptian natural gas to power stations in Israel.
There have been five attacks on the pipeline in the past six months. As a result, Israeli power stations have been forced to run for long periods on more expensive and less environmentally friendly sources of energy.
The Egyptian Army had already reinforced its security forces in Sinai by two battalions, with Israeli authorisation. The decision to position a much larger force in the area and to go on the offensive was taken after Islamist groups, calling themselves "Al Qaida in Sinai", began to operate openly in the peninsula.
Last month, the Al Qaida affiliate group attacked a police station in the town of El Arish on the Mediterranean coast, killing five people, including two officers.
In clashes with the terrorists so far, at least one man has been killed and the Egyptian forces uncovered a clandestine weapons factory near El Arish.