The revolution in Egypt has reached a sort of plateau stage: the threat of violent repression has receded and the regime has conceded the principle of democratic transition, but the opposition has been unable to generate the momentum to force the immediate departure of dictator Hosni Mubarak. The standoff can’t continue indefinitely, but there is no quick resolution in sight.

All of which puts the rest of the Middle East to some extent on hold as well, since across the region  autocrats and people are looking to Egypt for a lead as to the future of the region — just as Egypt’s uprising, although locally driven, was inspired by the example of Tunisia.

The term “domino effect” is a venerable and over-used one for this sort of situation: a relatively small incident sets off a chain reaction, and the gathering momentum topples progressively larger targets. Sometimes the theory seems to fit the facts quite well, as with accelerating speed of anti-communist revolt in eastern Europe in 1989. Other times less so, as with the original communist dominoes of Indochina.

So it’s not surprising that there has been plenty of talk of Middle Eastern dominoes, as Tunisia and Egypt have been followed by unrest in Yemen and Jordan, forcing concessions from their regimes, with further rumbles in Algeria, Syria and most recently Bahrain.

But there’s an important disanalogy here. Egypt is not just another Arab country; it is the unquestioned regional leader. It has roughly twice the population of any rival (currently Sudan is next, but with the secession of South Sudan that place will fall to Algeria), and Cairo is easily the largest city in the Arab world.

Egypt has a long tradition of intellectual and political leadership; graduates of its universities are prominent not just in the Middle East but in other Muslim countries, and its political trends have often been copied elsewhere. That’s why Egypt’s peace treaty with Israel was so traumatic for organised Arab politics, and why the Arab League eventually felt obliged to re-admit Egypt to full participation. (For a decade while Egypt was suspended the League had its headquarters, ironically enough, in Tunisia.)

Egypt’s only real rival for Arab prestige is Saudi Arabia: smaller in population but possessed of vast oil wealth and of the holiest sites in Islam. The Saudi monarchy has offered an alternative model of governance to Egyptian-style secular military rule: traditionalist and fundamentalist, more stable and even more ruthlessly repressive.

The big question for the coming months is whether the Egyptian contagion will spread to Saudi Arabia and the gulf states. With their much higher oil-induced per capita incomes they will hope they can hold off popular discontent; if not, the horizons for liberty will open even wider, with consequently larger headaches for Western policy makers.

But beyond that there are long-term effects to consider. If Egypt can establish a genuine democracy, the associated cultural ripples across the Muslim world could be profound. Turkey has already shown that democracy and Islam can work together, but the centrality of Egypt means that it could make that lesson much more powerful.