Scarred by decades of conflict and occupation, the craggy African nation of Eritrea has weathered the world's longest-running guerrilla war. The dogged determination that secured victory against Ethiopia, its giant neighbor, is woven into the national psyche, the product of cynical foreign interventions. Fascist Italy wanted Eritrea as the springboard for a new, racially pure Roman empire; Britain sold off its industry for scrap; the United States...