This is a weird issue that I've never been entirely sure how to address, which is why I've waited so long to write about it despite its prominence in Thai culture.
There are Ex-pats ("ex-patriots") living in all of the southeast Asian countries I visited, and undoubtedly many strike up relationships with locals. But it's at its most visible in Thailand, and it's always a falang man with a Thai woman, never a falang woman with a Thai man. To generalize a bit further, the man is usually 20 years older than the woman, and they often don't seem to have very clear channels of communication - and yet there are often indicators that the relationship is fairly long term (for starters, I wasn't wandering around the red-light district at night - I saw these couples in the middle of the day in the shopping districts). This kind of couple is common in Bangkok and Chiang Mai, and Nakhon Ratchasima (better known as Khorat) seems to be a favourite hangout for them - away from the tourists. I enjoyed Khorat for the same reason.
When I mentioned the issue to a female friend who had also just returned from southeast Asia, she said "That creeped me out too. Typically, they are men who wouldn't be considered all that attractive at home too. It's obviously a business deal of sorts--he gets sex, she gets money and status. (I don't mean that the girls are prostitutes, although I suppose some of them are.)"
Some women in Asia see foreign men as a way out of the country and a way to more financial security. But if that's the case, why did I see these couples in Thailand? Thailand is the economic powerhouse of southeast Asia, and Thais need financial help rather less than other southeast Asians. Is it something cultural about Thai women?
One day in a restaurant in Khorat frequented by ex-pats, I smiled at a fellow solo diner - a Thai woman about my own age. Our eyes had met and it's kind of a reflex response. This happened a couple more times, and when I left, she followed. A few blocks later I stopped to find out what was going on. She spoke to me in a mishmash of Thai and broken English, in which the only word I was actually able to distinguish was "you." So I said "No thankyou. Goodbye." This should have ended it, but she continued to follow despite my accelerated pace. I stopped again. I was still unable to follow what she was saying, but she wrote out a phone number for me. Excuse me? I can't understand you in person, how could we possibly communicate over the phone? I didn't take the number, and told her more vehemently "No!" She stopped following. What interested me (after I got over the creepiness) is the idea that we had any reason at all to associate when communication was clearly impossible. Perhaps she was looking for someone who didn't consider that a barrier, but what kind of relationship does that get you into?
Yet some of these couples are "real" couples, truly in love, maybe married for many years. This was also to be found in Khorat ... I talked to a woman there who met her husband while he was on leave from the Vietnam war, and they'd been married thirty years. They live in upper New York state, but were visiting Khorat because it's her hometown. I also know of a young American who met his wife at university in Georgia, but they currently live in her hometown, Bangkok.
Why Thailand? Why not Myanmar, Laos, Cambodia ...