 Activities undertaken by the USAF in Laos had to be approved by the US Ambassador to Laos William H. Sullivan.When the plan to install a navigation system on Phou Pha Thi Mountain was proposed, Sullivan initially opposed it as he thought that Laotian Prime Minister Prince Souvanna Phouma would not allow his country to be involved in an aerial offensive against North Vietnam.Souvanna Phouma did permit the installation, on the condition that it not be manned by US military personnel.