As Africa pours billions into new trade corridors, the rise and fall of the 19th-century Swahili corridors offer a warning.

Rural people mostly grew their own food. But in the city, the daily meal became a commodity to be bought and sold.

Scores of foreign nationals who traveled to a remote Indian Ocean island seeking adventure have become stranded there as simmering tensions between warring Yemeni parties and their backers disrupt ...