Following the establishment of 1ATF 's Nui Dat base in Operation Hardihood , standing patrols were established outside the base in the evening .
Clearing patrols sent out every morning and evening along the 12 - kilometre ( 7.5 mi ) perimeter .
Following the establishment of 1ATF 's Nui Dat base in Operation Hardihood , standing patrols were established outside the base in the evening and clearing patrols sent out every morning and evening along the 12 - kilometre ( 7.5 mi ) perimeter .