Why have many Middle Eastern nations had difficulty achieving unity since winning indepedence?

The correct answer is D) they have been beset by sectarian violence.

The other options of the question were A) they have been at war with their former colonial powers. B) the democratic governments rely on oil revenue. C) dictators have had problems transitioning to democracy

Many Middle Eastern nations had difficulty achieving unity since winning independence because they have been beset by sectarian violence.

That is exactly the case of Iraq, for instance. Once the Bush administration ordered the invasión of Iraq to capture leader Sadam Hussein, Iraq started a violent period where all the sects in the country started to confront each other and attached the US troops stationed in Bagdhad. Historians understood then, that the presence of a true dictator such as Hussein served to maintain the order in the nation, although through questionable methods.

the  seven  days  battles  were  a series of seven battles over seven  days from june 25 to july 1, 1862, near richmond, virginia,  during  the american civil war. the  seven  days ended with mcclellan's army in relative safety next to the james river, having suffered almost 16,000 casualtiesduring  the retreat.