The question is not very clear. But I believe that it intends to ask a comparison of the situation of the Middle East today, where you have lot's of conflicts, wars, disputes; and the reasons behind the same geography peacefully living for centuries under the the Ottoman times. If that's the case, my answer is below.
It is true that Middle East was (relative to the time of it's day), a lot more peaceful during the Ottoman period, compared to last hundred or so years. It is also important to note that there had been serious changes to the definitions of identity and nation during this period.
During the Ottoman period, the empire was a multicultural environment, where there was no absolute domination of a single ethnic or religious group in most of the regions and the cities. The identity was based on religion, not ethnic background, but there was a balance between different religious communities.
Firstly, with the rise of nationalism in Europe after the French Revolution, it didn't take long that ethnic differences started to gain an importance in the daily life in the Ottoman Empire. With the weakening of the Ottoman Empire, external powers (and especially Britain, France and Russia) have started to trigger the minorities of the empire, in order have better influences in the division of what is called the Sick Man of Europe, about to die.
Through these influences, especially the Christian minorities have gained economic and political privileges within the empire, which have later turned into nationalistic movements and ethnic conflicts. Metropolitan cities were shared by multiple ethnic groups, but later on claimed for one.
This has created serious conflicts between many groups and resulted in multiple wars before and after WWI.
Secondly, during the Cold War, the Middle East was positioned on a strategic place just near USSR, and became one of the strongest playgrounds of the rivalry between USSR and the USA. Radical religious movements were used against the communists. Intentionally and externally, conservatism is injected into the societies. But within decades, the radicalism had grown out of control.
Thirdly, once this radical religionism has started to threat the world, especially post 9/11, another external tailoring of the societies took place, which has targeted to divide the ethnic and religious groups. Unfortunately, this has only resulted in the enlargement of the influence of the radicals to all those countries. They were not model democracies before, but most were definitely far away from being extremists.
All these external touches to the Middle East have changed the social dynamics of the countries, in a manner like a mutation causing cancer difficult to fix. Unfortunately, the similar and unsuccessful involvements still take place today.