It will be reannexed as China former Province of Annam. Don't give China an excuse.If vietnam became a "strategic partner" of US it will become another afghanistan!!
As I says, Hanoi leadership are not that stupid like the Khmer Krom from the South.
One of the military objectives of the 1979 invasion was to demonstrate to Vietnamese that their protector and strategic partner won't show up. It didn't.
To lose sight of a forest because of one tree.