The attack on the Israeli embassy in Cairo yesterday was the most troubling sign yet that the Egyptian revolution could morph into something much less constructive and stable than many had hoped.The baseline analysis about the Egyptian revolution that many foreign analysts have accepted runs something like this. The effort by President Mubarak to convert Egypt into a dynastic state angered and alarmed virtually everyone in the country. The military, which did not welcome the prospect of a hereditary presidency, made the crucial decision not to crush protests. Mubarak resigned, and the military was left in control of a weakened state. In the future, the military system will continue with a few reforms; there will be a greater degree of public participation in government, but the military will remain the arbiter of politics, playing Islamists and liberals off against each other.This would make the Egyptian revolution a distinctly limited affair and would bitterly disappoint both liberals and Islamists, but might well provide a stable framework for the next stage of Egyptian development. The military’s interests and needs would suggest a basic stability in Egypt’s foreign policy. The military needs foreign aid; the economy needs tourism and foreign investment. A limited revolution would seek stability at home and abroad.To fight the natural tendency of the revolution to stagnate, radicals must find a way to stage events that shift public opinion and the balance of forces in their direction. During the French revolution events like the storming of the Bastille, the September massacres and the trial of Louis XVI moved the country onto a more radical path. The radicals took actions that divided moderates and aroused public sympathy even as they moved the revolutionary process to new heights.The storming of the Israeli embassy may work like that in Egypt. Most Egyptians have never accepted the idea of diplomatic relations with Israel (even many of those who don’t want more wars also don’t want what they see as the shame and surrender of an Israeli embassy on Egyptian territory). Attacking the embassy sends a thrill through the masses — who are, by the way, increasingly unhappy with the failure of the revolution to deliver tangible economic benefits.Attacking an embassy is a revolutionary act; it is a declaration that revolutionaries reject the international status quo and the current authorities who tamely agree to live within its limits. Like the Iranian seizure of the US embassy in 1979 it is an act that forces people to take sides. Parties and figures who condemn the attack on the Israeli embassy risk losing public support; those who accept it find themselves committed to an increasingly radical course.If, on the other hand, public opinion recoils from an act that threatens to cut Egypt off from needed foreign support and to devastate the tourist industry (forget Israeli tourists: few western sun worshippers like to visit countries where embassies are torched), the effort to radicalize the Egyptian revolution will lose steam.Either way, the embassy attack is more than a dramatic event. This is history on the march; keep your eyes on Egypt for the next few weeks.