[Brad from Tennessee]

I remember reading a book years ago about a veteran who returned to Vietnam in the 1970’s with American hybrid rice seed that became a great benefit to the country.

[Tainan]

Yep, that rice came from a US.Gov't sponsored program in the Philippines. Fact is, the rice growing program in VN was going on during the war there.
It was one of the several beneficial programs put into place by various US endeavors.
Of course after, the May 1975 debacle these programs were done away with by the communist regime and VN went from a rice-exporting country in a rice-importing country.
I believe this deficit status remained until the mid 90s or so. Sad tale.