When I was in Cairo during the Egyptian uprising, I wanted to change hotels one day to be closer to the action and called the Marriott to see if it had any openings. The young-sounding Egyptian woman who spoke with me from the reservations department offered me a room and then asked: "Do you have a corporate rate?" I said, "I don't know. I work for The New York Times." There was a silence on the phone for a few moments, and then she said: "Can I ask you something?" Sure. "Are we going to be OK? I'm worried."I made a mental note of that conversation because she sounded like a modern person, the kind of young woman who would have been in Tahrir Square. We're just now beginning to see what may have been gnawing at her -- in Egypt and elsewhere.Let's start with the structure of the Arab state. Think about the 1989 democracy wave in Europe. In Europe, virtually every state was like Germany, a homogenous nation, except Yugoslavia. The Arab world is exactly the opposite. There, virtually every state is like Yugoslavia -- except Egypt, Tunisia and Morocco.That is to say, in Europe, when the iron fist of communism was removed, the big, largely homogenous states, with traditions of civil society, were able to move relatively quickly and stably to more self-government -- except Yugoslavia, a multiethnic, multireligious country that exploded into pieces.In the Arab world, almost all these countries are Yugoslavia-like assemblages of ethnic, religious and tribal groups put together by colonial powers -- except Egypt, Tunisia and Morocco, which have big homogeneous majorities. So when you take the lid off these countries, you potentially unleash not civil society but civil war.That is why, for now, the relatively peaceful Arab democracy revolutions are probably over. They have happened in the two countries where they were most able to happen because the whole society in Tunisia and Egypt could pull together as a family and oust the evil "dad" -- the dictator. From here forward, we have to hope for "Arab evolutions" or we're going to get Arab civil wars.The states most promising for evolution are Morocco and Jordan, where you have respected kings who, if they choose, could lead gradual transitions to a constitutional monarchy.Syria, Libya, Yemen and Bahrain, countries fractured by tribal, ethnic and religious divisions, would have been ideal for gradual evolution to democracy, but it is probably too late now. The initial instinct of their leaders was to crush demonstrators, and blood has flowed. In these countries, there are now so many pent-up grievances between religious communities and tribes -- some of which richly benefited from their dictatorships while others were brutalized by them -- that even if the iron fist of authoritarianism is somehow lifted, civil strife could easily trample democratic hopes.Could anything prevent this? Yes, extraordinary leadership that insists on burying the past, not being buried by it. The Arab world desperately needs its versions of South Africa's Nelson Mandela and F.W. de Klerk -- giants from opposing communities who rise above tribal or Sunni-Shiite hatreds to forge a new social compact.The Arab publics have surprised us in a heroic way. Now we need some Arab leaders to surprise us with bravery and vision. That has been so lacking for so long.Another option is that an outside power comes in, as America did in Iraq, and as the European Union did in Eastern Europe, to referee or coach a democratic transition between the distrustful communities in these fractured states. But I don't see anyone signing up for that job.Absent those alternatives, you get what you got. Autocrats in Syria, Yemen, Libya and Bahrain shooting their rebels on the tribal logic of "rule or die." Meaning: Either my sect or tribe is in power or I'm dead. The primary ingredient of a democracy -- real pluralism where people feel a common destiny, act as citizens and don't believe their minority has to be in power to be safe or to thrive -- is in low supply in all these societies. It can emerge, as Iraq shows. But it takes time.Meanwhile, Saudi Arabia, which is 90 percent Sunni and 10 percent Shiite, has made clear that it will oppose any evolution to constitutional monarchy in neighboring Bahrain, where a Sunni minority rules over a Shiite majority. Saudi Arabia has no tradition of pluralism. When we say "democratic reform" to Saudi Arabia or Bahrain, we might as well be speaking Latin. What their rulers hear is "Shiites taking over from Sunnis." Not gonna happen peacefully.Even evolution is difficult in Egypt. The army overseeing the process there just arrested a prominent liberal blogger, Maikel Nabil, for "insulting the military."Make no mistake where my heart lies. I still believe this Arab democracy movement was inevitable, necessary and built on a deep and authentic human quest for freedom, dignity and justice. But without extraordinary leadership, the Arab transitions are going to be much harder than in Eastern Europe. Pray for Germanys. Hope for South Africas. Prepare for Yugoslavias.