U.S. Defense Secretary Leon Panetta heads to South America as part of Washington’s efforts to build partnerships in the region in the fight against drug trafficking and terrorism.  But the U.S. defense chief will also deal with the backlash of the scandal involving U.S. security personnel and Colombian prostitutes.

It is a region that is often out of U.S. headlines. But now, the worry that drug and human smuggling networks in the area may turn into a terrorist corridor is driving U.S. leaders to point their attention South.