I'm not entirely sure what you are asking but yes there was a trail, called the Ho Chi Minh trail, that ran partly through Laos and Cambodia to transport supplies and vietcong troops to south Vietnam.
Ground fighting occurred through out the Republic of South Vietnam. Unofficially, fighting occurred in Lao's and Cambodia along the South Vietnamese borders. Air Strikes occurred in North Vietnam, South Vietnam, Cambodia, and Laos.
Vietnam and Cambodia
Laos & Cambodia
The French .
Well considering it was in Vietnam and thousands of U.S. troops died, i would have to say the United States and Vietnam fought in the Vietnam War. Although, there was still a little involvement from the french but that was very limited. In addition to Vietnam, Laos and Cambodia had limited involvement while supporting the North Vietnamese.
North Vietnamese communists
Vietnam, with some fighting in Cambodia and Laos.
Cambodia had more bombs dropped on them than Laos during the Vietnam war. North Vietnamese solders would retreat into Cambodia and attack from there. Finally the US bombed North Vietnamese bases in Cambodia. They also established supply bases in Cambodia. Finally the US bombed the supply bases and supply lines into Cambodia.
Correct.
The NVA and the VC (North Vietnamese Army and the Viet Cong).
As a result of the Vietnam War, both Laos and Cambodia were destabilized. Their pre-war monarchies were replaced with Communist governments supported by Vietnam and China. In Cambodia, this government was the Khmer Rouge, which was later removed from power in 1979 by the Vietnamese. The Lao People's Republic remains in power to this day.
Cambodia is the country that lies directly north of Ho Chi Mien City, formerly Saigon. Cambodia was an important base of operations for the Vietnamese during the Vietnam War and was occupied by Vietnam from 1977-1991 after it was attacked by the Khmer Rouge.