North Vietnam had been infiltrating into South Vietnam since the 1950's. During the 1960's the troop movements were now more noticeable. Actual invasions resembling WWII, occurred in 1972 (in which US B-52 Bombers turned them back), and the North's final invasion in 1975 (in which the B-52's had been withdrawn) which won them the war.
NVA Troops had been invading South Vietnam by infiltration since the early 60's; operating in conjunction with local Viet Cong units. Conventional military invasions, using tanks, artillery, etc. were also routine in the late 60's, such as the battle between NVA PT-76 Light Tanks and the US Army's 1/69th Armor's M-48 Patton tanks at Ben Het in 1968, and the Battle at Lang Vei in 1968 when PT-76 Light Tanks over-ran the Green Beret outpost based there (See book: "Tanks in the Wire").
As US Forces steadily re-deployed from the country in 1972, NVA forces came down from the North WW2 style with tanks and artillery; but US Army General Abram's (the namesake of today's M-1 Abrams MBT) requested and received B-52 Stratofortess strikes against them, in support of the ARVN Army that were engaged against them. The NVA forces were annihilated by the B-52's.
By 1973, the NVA had re-grouped, re-organized, and prepared to do it again. This time there would be no B-52's to stop them; the US had completely re-deployed back to the US. NVA forces kept the pressure up on the South, and made a final conventional invasion of WW2 proportions that destroyed ARVN units, scattered others, and culminated on 30 April 1975 when NVA T-54/55 Main Battle Tanks went crashing through the South Vietnamese Capital's gates...parking on it's front lawn! The North had won! The war was over.
From 1954 to 1975, Vietnam was divided at the 17th parallel. In April, 1975, North Vietnam troops accepted the surrender of South Vietnam from its president, thereby unifying Vietnam into a single country.
The south
When the Vietnam War ended in 1975, North and South Vietnam became one communist nation called Vietnam.
Communist NORTH Vietnam wanted to re-unite with it's SOUTHERN half; SOUTH Vietnam. The US backed South Vietnam desired to remain a non-communist Republic of South Vietnam. Because the "Communists" were involved, and this was the cold war era; the US had to stop & contain communism. The North attacked the South, the South resisted...Vietnam War.
Democratic Republic of Vietnam (North Vietnam)
South Vietnam's surrender to North Vietnam is what ended the Vietnam War. The North Vietnamese had the goal of Vietnamese Unification and the surrender of South Vietnam in 1975 allowed them to achieve that objective.
1975 and reverse the statement.
Sigon
April 30th 1975 ; Saigon fell to the communists .
The fall of Saigon occurred on April 30, 1975.
At the South Vietnam Presidential Palace compound in Saigon on April 30, 1975 when North Vietnamese communist forces accepted the surrender of South Vietnam.
NVA tanks crashed thru their gates and accepted their surrender on 30 April 1975.
The capital, Saigon.
From 1954 to 1975, Vietnam was divided at the 17th parallel. In April, 1975, North Vietnam troops accepted the surrender of South Vietnam from its president, thereby unifying Vietnam into a single country.
Because the south was firmly defeated by the north (plus the south ran out of aviation and tank fuel & artillery ammunition after the US Congress cut off financial aid to them).
the north won and the south loss
There IS no North and South Vietnam, only Vietnam. After the US withdrew combat forces from South Vietnam, North Vietnam violated the peace agreement, invaded and conquered South Vietnam. Game over.