Joy reigned temporarily when Egyptian President Mohamed Morsi strayed off script at the Non-Aligned Movement summit in Tehran last week, and called for the ouster of Iran’s ally Bashar Al-Assad even with outside intervention.

Morsi’s position discomfited his Iranian hosts but undoubtedly pleased uncritical cheerleaders of the Egyptian version of the Arab Spring – a testimony either to their gullibility, or their cynicism about Israel, or both.

The Egyptian president undoubtedly redeemed himself in the eyes of New York Times’ columnist Thomas L. Friedman, who had fretted about the Egyptian leader’s “wrong turn” when he first announced his visit to Iran, and wrote: “This has nothing to do with Israel or Iran’s nukes. If Morsi wants to maintain a cold peace with Israel, that is his business.”

What had Friedman worried was that Morsi’s presence in Tehran would tarnish the image of the Arab Spring by legitimizing a savagely repressive Iranian regime that also functioned as the main enabler of Assad’s butchery. To judge by reactions in Egypt, what counted was Morsi’s dinging the Shi’ites rather than any defense of democracy.

Friedman’s attitude ignores the possibility that, far from representing an antithesis to Iran, Egypt under the Muslim Brotherhood is emulating it. Islamists in both countries hitched a ride on an antiauthoritarian revolution and upon reaching their destination chucked out the driver and took the wheel. They support democracy in the finest Leninist tradition – in the way the rope supports the hanged man.

Even assuming that Morsi’s government is moving toward democracy, Friedman’s position that Israel is of no concern in this equation is tragically reminiscent of revolutionaries ‏(including Jewish ones‏) in czarist Russia. They cheered on the anti-Semitic pogroms in the belief that it would school the Russian peasantry for bigger and better things against the hated autocracy. Bolstered by attitudes such as Friedman’s, important Egyptians are using the thaw in Iranian-Egyptian relations to openly declare an identity of views between the countries when it comes to Israel.

The Middle East Media Research Institute ‏(better known as Memri‏) recently provided translations of interviews broadcast on Iran’s Al-Alam Arabic TV service during the summit. In one, Ahmed Subei, a media adviser for Morsi’s Freedom and Justice Party, stated that the Camp David treaty should be reexamined in terms of “everything to do with ... [Egypt’s] sovereignty over its land.” A major deficiency, according to Subei, was that the treaty “isolated Egypt from the pan-Arab effort to liberate the land of Palestine, and to support Palestinian resistance.” In other words, once the treaty is dismantled, Egypt will be able to resume its role as a frontline country in the effort to liberate Palestine and extirpate Israel.

Also interviewed by Al-Alam last week was Prof. Gamal Zahran, head of the political science department at Egypt’s Port Said University, who opined: “Jerusalem is at the heart of the Palestinian cause, and the Palestinian cause is the cause of all Arabs and Muslims. The elimination of the Zionist entity is beyond debate ... By next year, Allah willing, Israel will be annihilated.”

Regime styles in our region change like hemlines. Monarchies gave way to the fascist developmental dictatorships called Arab socialism, and Islamic Democratic Republics are currently the current rage. Despite the presumed ideological kinship, rivalries between the regimes will remain, but hostility toward Israel will serve as a unifying factor.

The blueprint mentioned by the Egyptian interviewees is not something for the distant future; the process of emasculating the key demilitarization clause in what has effectively become a nonaggression pact has begun. Morsi initiated this assault when he introduced into the Sinai tanks and other weapons prohibited under Camp David without informing Israel. Quiet Israeli and American pressure prompted their withdrawal, but Egypt tellingly refused to concede that the weapons’ removal was part of Cairo’s commitments under the treaty. The official line was that the weapons had served their purpose and could now be pulled back, meaning that a sovereign Egypt could reintroduce them when it deemed proper.

These developments require a reappraisal by Israeli military planners of the future of the southern front. Cairo’s new course should also bolster skepticism about the feasibility of invoking the Egyptian demilitarization model as a substitute for Israeli sovereignty along the Jordan River and in the mountain ridges of Judea and Samaria.

Israel is confronting a creeping, 1936-style Rhineland crisis where, then as now, a demilitarization agreement is denounced as being incompatible with sovereignty, irrespective of treaty commitments. In the battle between sovereignty and security, unless we are dealing with a huge mismatch -- say Finland vs. the USSR -- sovereignty is trumps. Israel must therefore retain the sovereignty card in areas crucial for its security.

Demilitarization is frequently dependent on outside guarantors, but this too can be iffy, as the current situation with Egypt shows. During a crisis, the guarantor may be overstretched or conflict-weary, and may have made a political or emotional investment in the regime intent on revising the status quo. Moreover, the revisionist state may have seemingly better options than the guarantor ‏(by visiting China after Tehran, Morsi has effectively conveyed this message to the United States.‏)

So even as we welcome the new Egyptian ambassador, let us keep an eye on Morsi and the Sinai.

Political scientist Dr. Amiel Ungar writes a monthly column for Haaretz English Edition.