I took my wife with me to Vietnam in 2000 to visit the places I patrolled back then and I was struck by how most of the people were happy to see me and a couple even remembered me.
At one of the villages - An Trach - a local Catholic church had been rebuilt since the war. The priest asked me if I could help him buy a tractor for that village complex so the kids could attend school instead of tend buffaloes. The government wasn’t going to help them Since they had a Catholic school.
I went home and raised the money from the Marine Corps Base Quantico chapel (both Catholic and Protestant congregations) on one Sunday and we wired it to that priest. I cherish the photo he sent me of their new tractor.
They started doing business in the black market- regularizing it and bringing business savvy. They also formed consulting companies that government agencies contracted with at far higher expense than just hiring them. The Catholics became the business class and the tech experts.
Also- in the area south of Nha Trang which is a designated Catholic zone the government determined to build a string of plush resorts along the coast to capture foreign tourist money, principally Russian and Australian. They couldn't get enough labor for it.
In 2003 in Cam Đức there were young men sitting around tables drinking at midday- no work. In I believe, 05, the government solved its labor problem and tech expense problems by making the Catholics legal. In 2007 there were no young men hanging out drinking in Cam Đức.
In the meantime the Buddhists, being more rational than, say Moslems, saw how things worked with Catholics and imitated business practices- mainly they began to trust each other in business the way Christians do. Viets are naturally business oriented like Koreans.
Did you visit Cam Ranh? You should see it now. You would not it from what it was in 1970. If you peer around you will recognize the shape of Monkey Mountain but now Cam Ranh is a well laid out fairly prosperous town and the southern anchor of the divided 4 lane coast road that services those resorts all the way up to Nha Trang.