Operation Shed Light was a crash development project in aerial warfare, initiated in 1966 by the United States Air Force to increase the ability to accurately strike at night or in adverse weather. During the 1960s the United States military worked hard to interdict the movement of men and materiel along the Ho Chi Minh trail. The North Vietnamese were experts in the use of weather and darkness to conceal their movement, and understanding the superiority of American air power put their skills immediately to good use. US forces seeking to impede the steady flow of supplies attempted to locate largely static targets during the day with poor results.