Literature in English and Vietnamese, written by American POWs was left behind with the signs, banner, grenades and rockets. Pictures of the men with their name, rank and serial number accompanied their appeal for us to defect.
Opinions about the war were as varied among men in my unit as in the USA but I never heard anyone seriously say they would defect. Patriotism and military punishment if caught were both deterrents. No one in my unit could explain why Vietnamese on either side were fighting each other or us. They lived in the jungle with primitive medical care and little food, making our living conditions look great. I never saw a fat Vietnamese in any village or in the country, due to a general lack of food.
I believe 4 captured Americans were exchanged for enemy prisoners January 1, 1969 in a clearing close to Cambodia. I do not know if the exchanged Americans were those named on the surrender literature. Read the full story. https://vietnamsoldier.com/propaganda-and-pows/