Operation Off Balance was a hastily planned offensive operation of the Laotian Civil War; it happened between 1 and 15 July 1969 on the Plain of Jars in the Kingdom of Laos. The Royal Lao Government forces in Military Region 1 of Laos had just been evicted from the crucial all-weather airfield at Muang Soui, as well as most of the Plain, on 28 June 1969. Hmong General Vang Pao planned a quick counter-offensive to recapture the airfield from his communist foe; it would kick off on 1 July, supported by 60 sorties per day of tactical air strikes from Operation Barrel Roll.
In the event, the 1 July offensive ran afoul of its Neutralist allies, who retreated rather than carry out their assault. A constant flow of reinforcements from the attacking People's Army of Vietnam fed their own strength to resist. With the Neutralists' abstention, the remaining forces in Off Balance—two battalions of Hmong guerrillas and a Royalist paratrooper battalion— were defeated by counterattacking communist tanks supported by heavy artillery. During the battle, the Hmong suffered the loss of their only fighter pilot, Lee Lue. The reputation he had gained while flying over 5,000 combat missions had become the symbol of Hmong resistance; his death was a crushing blow to Hmong morale. Operation Off Balance ended the day of Lee Lue's burial. The communists still held the Plain of Jars and Muang Soui.
After World War II, France fought the First Indochina War to retain French Indochina. As part of its loss of that war at Dien Ben Phu, it freed the Kingdom of Laos. Laotian neutrality was established in the 1954 Geneva Agreements. When France withdrew most of its military in conformity with the treaty, the United States filled the vacuum with purportedly civilian paramilitary instructors. A North Vietnamese-backed communist insurrection began as early as 1949. Invading during the opium harvest season of 1953, it settled in northeastern Laos adjacent to the border of the Democratic Republic of Vietnam.