 The main problems were the pressure of time and the desire of the U.S. president for secrecy . The Cambodian monsoon , whose heavy rains would hamper operations , was only two months away . By the order of the president , the State Department did not notify the Cambodian desk at the US Embassy , Saigon , the Phnom Penh embassy , or Lon Nol of the planning . Operational security was as tight as General Abrams could make it . There was to be no prior U.S. logistical build @-@ up in the border regions which might serve as a signal to the communists . U.S. brigade commanders were informed only a week in advance of the offensive , while battalion commanders got only two or three days ' notice . 
