The opposite side did win.
the south would hate the north for several years because the north stopped slavery. until tractors,etc,came around. And during the time they would not vote or vote opposite of the north.
The opposite of first might be last, or the concept might have no opposite..... "Who was the first person to set foot on the moon?" has no opposite.
They would lose
If the North didn't want to talk at the peace table, bombing missions over the North Vietnam were stepped up. If the North conducted large offensive operations in South Vietnam, more bombing. If the North hinted they might want to talk, the bombing might be suspended for awhile.
Anything MIGHT have happened. You can speculate all you wish.
There might NOT be an all voluteer military; you couldn't vote in the coming election unless you were 21 years old.
There might not be an opposite.
The opposite of over might beundercontinuing
"Dangerous" might not be the right word for a politician, Ho was simply a determined leader.
You might see volcanic action.
The opposite of girls might be women or boys.
The only big lesson learned was North Vietnam was not invaded. During the Korean War, N. Korea was invaded; that brought in Red China. That strategy was not repeated in the Viet War.