Answer:
Land
Step-by-step explanation:
Land has been the main reason for conflict throughout human history, and the Middle East is no exception to this rule.
In particular, some areas of the MIddle East are rich in natural resources like oil, and natural gas, which makes them desirable to the regional powers.
Another issue is that many Middle Eastern countries are artificial creations that agglomerate different peoples who are often at odds with each other. Two examples are the countries of Iraq and Syria.