If you mean "why was the Vietnam War" a desireable place to fight a war; it wasn't. The US Military wanted to fight a war in Europe. Clean, traditional, and gentlemanly.
Wars in Asia are hot, dirty, and fought to the death...not the type of war Americans & Europeans like. (There were no "Hogan's Heros" (TV POW comedy series 1960s) in the Pacific! (WWII).
That was a desireable goal.
Current example
in Vietnam.
Vietnam
The takedown is generally considered more desireable. sales@countrygunsmith.net
because it was north Vietnam against south Vietnam
Vietnam.
South Vietnam was considered an ally of the US.
Because it took place in Vietnam
Plentiful water, annually rejuvenated fertile river plains, high food production, growing prosperity.
in the place that its raining
South Vietnam, North Vietnam, Laos, and Cambodia.