harris: defense secretary james mattis is paying a visit to the small african country djibouti, home to the only u.s. permanent base on the continent as well as 4,000 american service members. it is a strategic link in the fight against terror. base can serve as a launch pad for operations in yemen and somalia. paul tilsley is reporting live from johannesburg south africa. what prompted the trip at this time? >> reporter: well, harris, it's all about president trump's war on terror. secretary of defense mattis is showing himself to be a man on a mission. he's on a two-pronged attack, diplomacy with djibouti officials and get up and go get them pep talk at the camp lemmonier base. 4,000 u.s. personnel are mounting raids on al qaeda groups in yemen to the northeast and immediately to the southeast in the isis linked al-shabaab in somalia.