Final answer:
Britain's control over various Middle Eastern territories after World War I, through the mandate system, led to conflicting commitments and regional resentment. Their influence waned post-World War II, particularly after the Suez Crisis, with the U.S. taking a more dominant role. Britain's alignment with certain countries also shifted the regional balance of power.
Step-by-step explanation:
Britain's involvement in the Middle East and their contribution to the change in the balance of power in 1971 can be traced back to the aftermath of World War I. The dissolution of the Ottoman Empire and the implementation of the mandate system by the League of Nations facilitated British dominance in the region. Britain was granted mandates over Iraq, Palestine, and Transjordan, while France took control of Syria and Lebanon. Britain's commitments, such as supporting Arab control of Palestine, the Balfour Declaration, and the establishment of an independent Arab state as promised in the Sykes-Picot Agreement, were often at odds and stirred up resentment among both Jewish and Arab populations.
Post World War II, Britain's influence began to wane with events such as the Suez Crisis of 1956, leading to a shift in power dynamics, as the United States took a more assertive role, particularly after the resolution of the crisis. Moreover, the creation of the Baghdad Pact, which aligned Iraq, Iran, Turkey, Pakistan, and Britain, was perceived by Egypt's Nasser as an attempt to elevate Iraq over Egypt in the region, further altering the balance of power. Britain's ability to influence the region diminished as new alliances were formed, and the United States and the Soviet Union became increasingly involved in Middle Eastern affairs.