From 1964 to 1973, the peak years of the prolonged IndoChina War (1962-1975), two Thai army officers ruled Thailand and allowed the US to establish several army bases within Thai borders to support the US campaign in IndoChina. During this time, Bangkok was host to many American GIs on Rest and Recreation (R&R) stationed throughout Southeast Asia.
Interestingly, Thailand continues to be a go-to R&R spot for the likes of development and foreign assistance workers today. It seems everyone in the foreign assistance community has an Thai adventure or story to share. Some of our friends who were stationed in Bangladesh for several years reported heading straight to Thailand for R&R every chance they got - they ended up visiting Thailand 9 times over a two year period. The idyllic settings seem to pull people back time and time again.
References: Lonely Planet: Bangkok City Guide