We never declared victory in Vietnam, and neither did the Soviets in Afghanistan. We turned the Vietnam War over to what remained of the South Vietnamese army, which was then defeated by the Viet Cong and the North Vietnamese within two years. The retreat by the Soviet army from Afghanistan was al thousand kilometers long, body bags in tow. There are several graphic documentaries of it.
You don't have any Vietnam vets in the family do you?
"We declared victory in Vietnam and then packed up and left." is heard at every family gathering. It's sardonic humor.
Were you around back then? Do you remember the wild rooftop parties?
and the chaotic victory celebrations on the ships off the coast
We have another victory celebration coming up soon in Afghanistan.
New war, new generation. Same as it ever was.
The gist of my post (minus the attempt at humor) was:
Neither of those "wars" were existential actions by either of us, they were just side actions in the US/Soviet Cold War - the REAL war
If Vietnam had been a real war we would have mined Haiphong during the war to cut off the north's resupply and not waited until 1972 when we were already declaring victory and heading out the door.