The anger of demonstrators in Tunisia and Egypt runs, too, through 25-year-old Saleh Barek al-Jabri.

Mr. Jabri, the son of a Yemini bus driver, says he answered his government's call for young people to study petroleum engineering, enrolling in a course at Yemen's Hadhramaut University for Science and Technology. Officials visited his school to offer encouragement. An oil minister came through to promise jobs. Mr. Jabri excelled, finishing fifth in his class.

But...