That blunt show of force confronted Mr. Obama with the limits of his ability, or his willingness, to midwife democratic change. Despite a global outcry over the shooting and tear-gassing of peaceful protesters in Bahrain, the president largely turned a blind eye. His realism and reluctance to be drawn into foreign quagmires has held sway ever since, notably in Syria, where many critics continue to call for a more aggressive American response to the brutality of Bashar al-Assad’s rule…

To some, the stark difference between the outcomes in Cairo and Bahrain illustrates something else, too: his impatience with old-fashioned back-room diplomacy, and his corresponding failure to build close personal relationships with foreign leaders that can, especially in the Middle East, help the White House to influence decisions made abroad.