I begin by saying that of course, the greatest tragedy of the Korean and Vietnam (Indochinese) Wars were 3 and 3-5 million people slaughtered in the fighting.

However, an OCD part of me has always found something uniquely tragic about the fact that Korea, despite being a recognizably unified nation situated on the Korean peninsula for more than a millenia before the Korean War, ultimately is the nation still divided today, while Viet Nam as we know it today is really a merger between Dai Viet in the north and Champa in the south that was only really completed by the early 1800s. Sure lots of the Champa coast was conquered over hundreds of years, but still, the Southern part of Viet Nam being part of Viet Nam was at the time of the fighting was just barely over a century old, something of a blink in terms of history when we're talking some of the oldest civilizations on earth.

So my question is, why the hell did Ho Chi Minh and co. care so much about taking South Viet Nam when, unlike in Korea, it wasn't a millenia-old integral piece of the nation, but really something more of a modern addition to the state?

Was it because Ho didn't want North Viet Nam reduced to a Chinese satellite? Was there some issue of national pride?

I mean I figure these were partial reasons, but I guess what I'm asking is: given that Champa had its own separate history and culture closer tied to India than China for so long before the 19th century, why did Ho consider South Viet Nam, "Vietnamese-enough" to fight such a bloody war over it with the US?