to assist by tracking suspicious ships or participating in raids. Escort of USN aircraft carriers involved in Operation Rolling Thunder airstrikes. Although RAN ships on deployment were expected to fulfil all duties of an equivalent American destroyer, they were forbidden by the Australian government from operating outside the Vietnam theatre on unrelated Seventh Fleet duties (such as the Taiwan Patrol Force, guard ship duties at Hong Kong, or the Space Recovery Program). After the invasion of Cambodia in 1970, RAN ships were also prohibited from entering Cambodian waters. While deployed to Vietnam, the destroyers were placed under the administrative control of Commander Australian Forces Vietnam in addition to that of the Flag Officer Commanding Australian Fleet. Operationally, the RAN vessels were under the command of the United States Seventh Fleet. Arrangements were made to provide logistic support through the United States Pacific Fleet. A USN lieutenant was assigned to each ship during deployments to act as a liaison with the Seventh Fleet. The deployment of in March 1967 began a pattern of six-month deployments for RAN destroyers, with a constant RAN presence with the Seventh Fleet. Australia was the only allied nation to provide naval support to the United States Navy during the Vietnam War. First deployment On 14 September 1967, Vietnam duties were handed to Perth by Hobart. The destroyer's first assignment was the gunline off the II Corps operating area, where Perth rendezvoused with on 26 September. The ship was specifically tasked with providing gunfire support for the 1st Cavalry Division of the United States Army, which was involved in Operation Pershing. Three days later, Perth was reassigned to the northern part of South Vietnam, in response to increased North Vietnamese activity. On 2 October, both turrets broke down; both were repaired by 23:00, but the aft turret failed again the next evening, with the new problem beyond repair until replacement parts were air-dropped on 5 October. Perth was redeployed to Sea Dragon operations on 16 October, joining American cruiser . On the morning of 18 October, the destroyer was fired on by coastal artillery while investigating a group of fishing junks; Perth was hit once, with the shell deflecting off the aft gun turret and penetrating the superstructure to start a fire in the confidential books vault. The gun turret captain was later awarded a Distinguished Service Medal for his actions in response to the attack, while