Batatu started studying Iraqi history in the 1950s, taking a particular interest in the revolutionary movements that were then prominent in that country and especially in the Iraqi Communist Party. From the late 1950s on he traveled to Iraq several times, and succeeded in having access to communist political prisoners and secret police files before the revolution of 1958. He was allowed access to security service archives from various periods of Iraqi history, up until the 1970s, and used this and his considerable range of personal contacts with figures from different political movements to compose his study of political change in Iraq, ''The Old Social Classes and New Revolutionary Movements of Iraq'' (published in 1978). This work, although largely focusing on the Iraqi Communist Party, also provides a wealth of information about the other revolutionary movements in the country as well as the ruling classes prior to 1958, and is considered one of the fundamental works on modern Iraqi history. Batatu's methodology is grounded in political sociology and considers in detail the social factors for the developments he covers, and even more so the social composition of the movements in question.
Batatu also undertook a similar study of Syria, ''Syria's Peasantry, the Descendants of Its Lesser Rural Notables, and Their Politics'' (published in 1999).