I lived and taught at international schools in wartime Vietnam (was evacuated at the fall in 1975), Thailand, Saudi Arabia, Iran (just before Shah overthrown), Korea, Venezuela, Liberia, Egypt, Jordan, Cambodia, and Singapore. I included teaching in the US also.
I was in Singapore for 25 years, but only teaching 20 of those years while calling it home. I maintained my home there and traveled to Egypt and Jordan to teach. I returned to Singapore last year only to decide to not retire there but live in the States. My own country is a foreign one for me, and I always have the option to return overseas again. Travel is always available.
I would not recommend retiring in any of those countries, although Singapore was home for me, and I was a permanent resident there. The housing situation can be expensive, and it is very densely populated, quite different from the Singapore I knew in 1988. However, I traveled summers in Malaysia. I even got the Malaysian retirement visa, called MM2H. I gave that up, knowing that it is easy to get later on. I gave it up mostly because I disliked the requirement of having US$50,000 in a local bank. Next time I would go there on the pension scheme. Also, being a dog lover, Malaysia is not the place to be. I visited Thailand, and met so many expats retired there, and they love it. That's always a possibility in the future for at least part of the year.
Rob