The World in Photos This Week

The United States retreats from the cliff; Chadian soldiers cross the border; a town in Spain has a flour fight.

JANUARY 4, 2013

Shark fins dry in the sun on the roof of a factory in Hong Kong on Jan. 2. Hong Kong has one of the world's biggest markets for shark fins, which are used to make an expensive soup that is popular in China. Biologists have raised concerns that the overharvesting of fins is causing an environmental calamity. 

ANTONY DICKSON/AFP/Getty Images